North America Climate – Sep 2026September 2026 Update
North America experienced widespread, unusual warmth as summer turned to autumn, driven by extraordinary heat across the central and southern reaches of the continent…
Top 5 Countries: United States, Canada, Mexico, Cuba, and Guatemala
Data for Continents is averaged from country snapshots. See Methodology.
Summary
North America experienced widespread, unusual warmth as summer turned to autumn, driven by extraordinary heat across the central and southern reaches of the continent. Eight of the ten highest monthly temperature anomalies across all tracked global regions occurred in US states, while tropical cyclone activity struck Mexico, where a storm is monitored on our live tracker at Extreme Weather tracker. Climate patterns across the continent were bolstered by a strong El Niño, which is forecast to peak at Very Strong in Sep-Nov on our ENSO tracker, paving the way for further temperature and precipitation shifts in the coming months.
This month in numbers
North America recorded a 1-month average temperature anomaly of +2.57°C above the 1961-1990 baseline. Over the broader 3-month period, the group anomaly stood at +2.04°C, while the 12-month rolling average reached +1.86°C. In the cross-region rankings, the continent demonstrated exceptional warmth: 8 of the 10 highest monthly temperature anomalies in the world were recorded by US states, led by Oklahoma at +5.87°C above average. Over the 12-month period, US states also accounted for 7 of the top 10 warmest regions globally, highlighting sustained high temperatures across the continent.
Hottest & coolest countries
The warmest country relative to its baseline was El Salvador (), which reached an average temperature anomaly of +3.21°C. Canada () followed closely at +2.69°C above normal, with Jamaica () recording +2.55°C and Mexico () at +2.51°C. At the cooler end of the spectrum, Greenland () stood out as a rare exception across the region, logging an anomaly of -0.48°C below its baseline.
What's driving change?
The dominant driver behind the widespread warmth across North America is ENSO, with a strong El Niño recording a 3-month RONI anomaly of +1.69°C and a 100% probability of persisting through the coming seasons on our ENSO tracker. The atmospheric wave response associated with the Pacific-North American Pattern helped channel tropical warmth across central and eastern regions of the continent. Furthermore, the physical mechanism that amplified high daytime temperatures over interior landmasses, worsening soil drying and compounding late-season heat across the United States and Mexico.
Looking ahead
Seasonal forecasts indicate that above-average temperatures are likely to persist across much of central and eastern North America through the late autumn and early winter months, as El Niño continues to influence regional atmospheric circulation.
Precipitation, Sunshine, Frost and Snow are converted to standard deviations from their own average so they can share an axis with Temperature anomalies.
Metric
Insight
Temperature
10-Yr AverageActual Year
Climate History
58 of 58 events
1912Volcanic
Novarupta (Katmai) eruption
The largest volcanic eruption anywhere in the world in the 20th century - 13 km3 of magma, about thirty times the 1980 Mount St. Helens eruption - at Novarupta in Alaska on 6-8 June 1912. Ash reached 100,000 ft and cooled the Northern Hemisphere by roughly 0.3°C over 1912-13. Unlike a tropical eruption such as Pinatubo, a high-latitude eruption's haze stays in its own hemisphere, so it did little to the Southern Hemisphere.
After the Second World War, coal and oil use grew rapidly across Europe, North America and the Soviet Union. Global sulphur dioxide emissions rose from about 30 to about 130 million tonnes a year by 1980, and the sulphate haze they formed masked part of the greenhouse warming underneath - the effect known as 'global dimming'.
One of the strongest La Niñas since instrument-based ENSO records begin in 1950, and part of a run of cool Pacific years through the mid-1950s. La Niña cools global temperatures slightly for a year or two while it lasts, and shifts rainfall patterns worldwide.
Charles David Keeling begins continuous measurements of atmospheric CO₂ at Mauna Loa Observatory in Hawaii, starting at about 315 ppm. The record has risen every year since and is now the longest unbroken direct measurement of CO₂ anywhere - the 'Keeling Curve'.
Hurricane Hattie struck British Honduras, now Belize, on 31 October 1961. Its winds and storm surge damaged about 70% of the buildings in Belize City, killed 307 people and left more than 10,000 homeless - destruction that led the government to build a new capital inland at Belmopan.
In October 1963 Hurricane Flora looped slowly over eastern Cuba for four days. Santiago de Cuba recorded 2,550 mm of rain, the highest total from any event in Cuban records, and floods killed about 1,750 people in Cuba. In all, across Haiti, Cuba and the Dominican Republic, Flora killed more than 7,000 people.
One of the strongest El Niños on record. It contributed to failed grain harvests in the Soviet Union and elsewhere in 1972, and to a sharp rise in world food prices - an early sign of how far ENSO's reach extends.
The Pacific Decadal Oscillation - a slow natural cycle in North Pacific sea temperatures - switches from its cool to its warm phase in 1976-77. The change was abrupt enough to be called the 1976-77 Pacific Climate Shift: it warmed Alaska and the west coast of North America, and reorganised North Pacific fisheries.
Global sulphur dioxide emissions peak at about 130 million tonnes a year, then begin a long decline as Europe, North America and Japan clean up their air. As the aerosol mask thins, the rate of global warming picks up through the 1980s.
Hurricane David struck the Dominican Republic as a Category 5 storm on 31 August 1979, the most intense hurricane to make landfall there on record. Floods and mudslides killed more than 1,000 people, perhaps 2,000; at Padre Las Casas hundreds who had roped themselves together to climb to safety were swept away when a dike broke.
A sulphur-rich eruption in Mexico whose aerosol cloud stayed in the stratosphere for more than two years, cooling the Northern Hemisphere by about 0.2°C.
The strongest El Niño since 1950 on NOAA's Relative Oceanic Niño Index, which strips out the background warming of the tropical oceans before ranking events. On the older index that leaves that warming in, 2015-16 comes out on top instead.
British Antarctic Survey scientists Joe Farman, Brian Gardiner and Jon Shanklin publish their Halley and Faraday measurements on 16 May 1985, showing October ozone over Antarctica had fallen to about two-thirds of earlier decades. The cause is traced to chlorofluorocarbons, and the finding triggers the fastest international environmental response on record.
Signed in 1987 to phase out ozone-depleting chlorofluorocarbons, the Montreal Protocol turned out to be one of the most consequential climate treaties ever agreed. CFCs are potent greenhouse gases in their own right, and NOAA estimates the Protocol prevented up to 2°C of warming by 2100 - around 1°C from the emissions avoided, and up to 1°C more by sparing forests and other carbon sinks from increased ultraviolet radiation.
Atmospheric CO₂ passes 350 ppm. In the same year James Hansen told a US Senate committee that global warming was already detectable, the moment it entered mainstream politics. Twenty years later, in 2008, Hansen proposed 350 ppm as the safe upper limit - a level the world had already left behind.
One of the strongest La Niñas on record, arriving straight after the 1986-87 El Niño - a swing from one extreme of the Pacific cycle to the other in barely a year.
Hurricane Gilbert crossed the whole length of Jamaica from east to west on 12 September 1988 - the most destructive storm in the island's history. More than 100,000 homes were damaged or destroyed, 45 people died and 800,000 took shelter. Gilbert went on to set the lowest pressure then recorded in the Atlantic before striking Mexico's Yucatán peninsula.
Daytime warming catches up with the night-led pattern
Across 1961-90, 81% of the world's land saw nights warming faster than days. Across 1991-2020 the pattern reversed: 70% saw days warming faster, as the industrial haze that had been dimming daytime sunshine was cleaned up. The study compares two fixed thirty-year windows; measured as a turning point, this site's own global series turns around 1982.
Mount Pinatubo in the Philippines erupts in June 1991, the largest eruption since 1912. Its sulphate haze cooled global surface temperature by about 0.5°C in 1992 and reduced rainfall over land for about two years, before the warming trend resumed.
Atlantic Multidecadal Oscillation flips to a warm phase
The Atlantic Multidecadal Oscillation - a slow natural cycle in North Atlantic sea temperatures, roughly 60-70 years long - flips to its warm phase in 1995. Warm phases are linked to more active Atlantic hurricane seasons, wetter summers in parts of north-west Europe and more frequent drought in the central and western United States.
One of the strongest El Niños on record, and the one the textbook El Niño pattern is usually drawn from. It pushed 1998 to what was then the warmest year ever measured, and set off the first global-scale coral bleaching event.
For five days in January 1998 freezing rain coated eastern Ontario and southern Quebec in ice, bringing down power lines and pylons. About 1.4 million customers in Quebec and 230,000 in Ontario lost power, some for weeks; as many as 35 people died and the army deployed 16,000 troops. The year as a whole was mild: 1998 is Canada's 5th-warmest in this site's 1950-2025 record, helped by the very strong 1997-98 El Niño.
Hurricane Georges crossed the Dominican Republic and Haiti in late September 1998. Floods and mudslides killed several hundred people in the Dominican Republic and left more than 155,000 homeless - its costliest hurricane - and more than 600 died across the Caribbean.
Hurricane Mitch stalled over Central America in late October 1998, dropping historic amounts of rain on Honduras, Nicaragua and Guatemala. Floods and mudslides killed more than 11,000 people, making it the second-deadliest Atlantic hurricane on record.
A strong La Niña that ran for three winters after the record 1997-98 El Niño, peaking at an ONI of -1.53. It pulled global temperatures back below 1998's record for several years, and brought the usual La Niña pattern of dry winters across the southern United States and wet years in Australia and Indonesia.
Pacific Decadal Oscillation flips back to a cool phase
The Pacific Decadal Oscillation - a slow natural cycle in North Pacific sea temperatures - flips back to its cool phase around 1998-99. The cool phase that followed is one reason global surface warming appeared to slow in the 2000s, as more heat went into the deep Pacific.
A moderate-to-strong El Niño that peaked around the turn of 2009-10. It helped make 2010 one of the warmest years on record at the time, and was followed straight away by the strong La Niña of 2010-12.
On 7-8 November 2009, as Hurricane Ida passed offshore, a low-pressure system dropped 355 mm of rain in four hours on central El Salvador. Floods and debris flows killed 194 people, left 80 missing and forced 15,000 from their homes; boulders and mud tore through the town of Verapaz below the San Vicente volcano.
Globally, heatwave days have roughly doubled each decade since 2010 - from an average of 5.3 a year in the 2000s to 11.5 in the 2010s and 18.9 so far in the 2020s, weighted by land area across 169 countries. El Niño has not become more extreme. The whole temperature distribution has shifted upwards, so the same natural El Niño and La Niña cycle now pushes far more days over fixed extreme-heat thresholds.
A strong double-winter La Niña peaking at an ONI of -1.57. It gave Australia its wettest two years on record and the Queensland floods of 2010-11 - so much rain fell on land that global sea level briefly dropped in 2011 - and it fed drought in the Horn of Africa and in Texas.
On 11-12 July 2012 about 97% of the Greenland ice sheet's surface was melting - including the summit, where ice cores show melt that widespread had not happened since 1889. The previous satellite-era maximum was about 55%.
Atmospheric CO₂ passes 400 ppm at Mauna Loa on 9 May 2013 - a level the planet had not seen for 3-5 million years, since the Pliocene, when sea levels were many metres higher.
In June 2013 heavy rain on the Rocky Mountain foothills, falling onto late snow, sent the Bow and Elbow rivers through Calgary and neighbouring towns. About 100,000 people were evacuated, and at around C$5 billion it was, until the Fort McMurray fire, the costliest disaster in Canadian history.
The strongest El Niño on record by raw ONI - though on NOAA's newer RONI index, which strips out background tropical-ocean warming, 1982-83 ranks slightly ahead instead. 2016 became the hottest year on record at that time (+1.0°C above pre-industrial).
The eleven warmest years ever measured are 2015 through 2025, an unbroken run - the longest sustained stretch of record warmth in the 176-year instrumental record. 2023 and 2024 each broke the previous record in turn.
On 3 May 2016 a wildfire swept into Fort McMurray, Alberta, forcing about 88,000 people to leave - the largest wildfire evacuation in the province's history. At around C$9 billion it remains the costliest disaster in Canadian history.
Hurricane Matthew hit south-western Haiti as a Category 4 storm on 4 October 2016, killing more than 500 people there. It was the worst disaster in Haiti since the 2010 earthquake and the deadliest Atlantic hurricane since Stan in 2005.
On 24 November 2016 Hurricane Otto crossed the Nicaragua-Costa Rica border - the first hurricane on record to make landfall in Costa Rica, and the southernmost ever to hit Central America. Its rain killed ten people in Costa Rica, and four in Panama as it approached.
Hurricane Irma hit Cuba's north coast on 8-9 September 2017, the first Category 5 hurricane to make landfall on the island since 1924. It battered the coast from Camagüey to Havana, where seawater flooded the Malecón; the evacuation of close to a million people kept the death toll to ten.
Hurricane Maria crossed Puerto Rico on 20 September 2017, knocking out the whole island's power grid, in places for months. The official death toll was later revised from 64 to 2,975, from a study of excess deaths in the six months after the storm.
On 18-19 October 2018 about a month's rain fell on Trinidad in two days, causing what was reported as the island's worst flooding in 50 years. Between 100,000 and 150,000 people were affected, with Sangre Grande, Tunapuna-Piarco, Couva-Tabaquite-Talparo and Mayaro-Rio Claro worst hit, and the Uriah Butler Highway across the Caroni plain under water.
Hurricane Dorian struck the Abaco Islands on 1 September 2019 with 185 mph winds, the strongest hurricane on record to hit the Bahamas, then stalled over Grand Bahama for about a day. The confirmed death toll is 74, with hundreds more reported missing, and damage was put at US$3.4 billion.
Global fossil CO₂ emissions fell about 5.8% in 2020, from 37.0 to 34.8 billion tonnes, yet atmospheric CO₂ still rose 2.5 ppm - the dip barely registers in the atmospheric record. Emissions were back to pre-pandemic levels by 2022.
New international shipping rules cut the sulphur allowed in ship fuel from 3.5% to 0.5% almost overnight, removing about 8 million tonnes of sulphur dioxide a year. With less sulphate haze over the oceans, it may have added around 0.1°C of warming by 2023-24.
Three consecutive La Niña winters - a 'triple dip', which has happened only a handful of times since 1950 - peaking at an ONI of -1.11. It held global temperatures slightly below where the warming trend would otherwise have put them, and coincided with five failed rainy seasons in a row in the Horn of Africa and severe flooding in eastern Australia in 2022.
In November 2020 two Category 4 hurricanes, Eta and then Iota, made landfall on Nicaragua's Caribbean coast within two weeks and about 25 km of each other - something without precedent in the Atlantic. Their floods and landslides across Central America left more than 300 people dead or missing and affected more than 6.5 million.
On 29 June 2021 the village of Lytton, British Columbia, reached 49.6°C - the highest temperature ever measured in Canada, and 4.6°C above the previous national record, set in 1937. It was the third day running that Lytton broke the record. The next day a wildfire destroyed most of the village.
Five years after Maria, Hurricane Fiona struck Puerto Rico on 18 September 2022 and knocked out the entire island's power, leaving 1.5 million customers in the dark. Up to 22 inches of rain fell in places, bringing catastrophic floods across the south and east.
A strong El Niño arriving on top of long-term greenhouse warming, with the cut in shipping sulphur from the 2020 fuel rule adding a little more. Together they produced the record global temperatures of 2023 and 2024.
Canada's 2023 fires burned about 18.4 million hectares - two and a half times the previous record, set in 1995, and more than six times the average of the past decade. Smoke reached as far as New York and western Europe.
Over the warm Pacific, Otis grew from a tropical storm to a Category 5 hurricane in about a day, far faster than forecasts expected, and hit Acapulco on 25 October 2023 with 165 mph winds - the strongest hurricane on record to make landfall on Mexico's Pacific coast. More than 50 people died.
El Niño brought Panama its second-driest year since 1950 in 2023. Gatún Lake, which feeds the canal locks, fell to its lowest level since at least 1995, and daily transits were cut from about 36 to 24 ships by November, delaying cargo worldwide.
2024 is Mexico's warmest year in this site's 1950-2025 record. From March to June 2024 a heat dome sat over Mexico during a deep drought. Dozens of places broke temperature records, Mexico City reached an all-time high of 34.7°C, more than 150 people died of heat, and howler monkeys fell dead from the trees in Tabasco and Chiapas. The Cutzamala reservoirs supplying Mexico City fell to about 30-40% of capacity, their lowest on record.
Hurricane Melissa made landfall in Jamaica as a Category 5 storm on 28 October 2025, with winds that at their peak tied the strongest ever measured in an Atlantic hurricane. It was the most intense hurricane on record to hit the island and its costliest disaster, with damage put at more than US$12 billion.
Warm Spell Duration Index (WSDI) - days in a 6+ day run above the local 90th-percentile temperature for that time of year. Equal-weight mean across 6 countries.
Heatwave days per year2024 (Record)10-yr avg
Data: World Bank Climate Change Knowledge Portal (ERA5-derived), aggregated by 4BYO across member countries. Refreshed roughly 1-2x/year, ~7-8 months behind present.
Source: Copernicus ERA5 (countries) · NOAA Climate at a Glance (continents, US states & climate regions) · Met Office (UK) · GPCC (rainfall, snow) · World Bank CCKP (frost). Anomalies are vs the 1961–1990 baseline. See methodology.
4byo continent aggregate · equal-weight mean of 6 country monthly absolute temperatures (OWID/CRU TS); precipitation: GPCC (DWD). - Anomalies vs 1901-2000 mean
How spring and autumn have shifted in North America. Spring is defined as the date monthly temperatures first rise above the long-term annual mean (3.6°C, from 1940–1969); autumn is the date they fall back below it. Temperature swings 28.7°C peak-to-peak across the year - a classic four-seasons rhythm.
Shifting summer
12 Days Longer
Warm Season
1940–1969 Baseline: 21 Apr → 24 Oct · 186 days
2016–2025 Now: 16 Apr → 30 Oct · 198 days
−5d+6d
JanJFebFMarMAprAMayMJunJJulJAugASepSOctONovNDecD
Spr 5 Days EarlierAut 7 Days Later
baseline avgrecent avgClickTap for decades
1940–19692016–20251940–1969 annual mean
Baseline vs recent monthly temperature climatology. Biggest warming: Jan (+3.0°C).
4byo continent aggregate · OWID/CRU TS country monthly temperatures & precipitation: GPCC (DWD). Baseline: first 30 yrs on record. Recent: last 10 yrs on record.
Live GDACS alerts in North America - Red (Major), Orange (Severe) or Green (Moderate) - and the long-term record of weather and climate disasters.
Live Alerts
Loading…
Alerts, Last 12 Months
Major
2
2.8 a year since 2021
Severe
3
5.3 a year since 2021
Moderate
409
Weather Disasters, 2025
Disasters
50
60 a year, 2016-2025
Deaths
737
945 a year, 2016-2025
Weather Disasters, 2016-2025
Most Frequent
Storms & Cyclones
363 of 597 disasters
Deadliest
Storms & Cyclones
4,854 of 9,445 deaths
Disasters: EM-DAT, CRED / UCLouvain, via Our World in Data - 10+ deaths, 100+ people affected, or a declared emergency or call for international help. Alerts: GDACS.
The natural climate patterns that measurably shape seasonal temperature or rainfall in North America, from this site’s own data since 1950 - long-term trends removed, and ENSO’s share taken out before scoring the others, so each is credited only for what it adds.
El Niño / La Niña (ENSO)moderate link
The tropical Pacific’s warm and cool swings - the biggest natural driver of year-to-year climate.
Now: El Niño (strong) · RONI +1.7°C(Jul-Sep 2026)
Forecast - 100% very strong at peak, Sep-Nov, then neutral by Apr-Jun 2027 (NOAA). La Niña from Sep 2027 in SNU’s AI model.
A moderate or strong link for 78% of the places in this group.
Every figure on this page is sourced from official, openly published climate datasets. Anomalies are calculated against the 1961–1990 baseline (temperature) and 1991–2020 (rainfall, sunshine, frost) - see the Methodology & Sources page for the complete dataset list and update calendar.
North America is warming in line with the rest of the world. The page above shows the latest monthly temperature anomaly versus the 1961-1990 baseline, the long-term annual trend, and the region's rank in the historical record. The headline panel also shows the long-term trend rate per decade and the warmest and coolest years on file.
Which climate drivers affect the weather in North America?
Measured from seasonal temperature and rainfall in North America since 1950, with the long-term warming trend removed (and ENSO's own share removed before scoring the other drivers), the climate drivers with a clear effect here are: El Niño / La Niña (ENSO) - a moderate or strong link for 78% of the places in this group; the North Atlantic Oscillation (NAO) - a moderate or strong link for 100% of the places in this group; the Pacific-North American pattern (PNA) - a moderate or strong link for 100% of the places in this group; the Arctic Oscillation (AO) - a moderate or strong link for 67% of the places in this group. Their current state is shown in the Climate Drivers section of this page.
What extreme weather affects North America?
In 2025, the latest complete year, the international disaster database EM-DAT recorded 50 weather and climate disasters in North America, against an average of 60 a year in 2016-2025, with 737 deaths. Over those ten years the most frequent type was storms & cyclones (363 of 597) and the deadliest storms & cyclones. GDACS, the UN and European Commission's disaster alert system, issued 2 Major (Red) and 3 Severe (Orange) alerts for North America in the last 12 months. Live alerts are on this page and on the Extreme Weather tracker.
Where does the climate data for North America come from?
Climate data for North America comes from Our World in Data, sourcing Copernicus ERA5 and HadCRUT5 (national temperature anomaly) and the Global Carbon Project via Our World in Data (CO₂ emissions), refreshed every month, when the upstream temperature and rainfall data are refreshed.
What is the climate baseline used on this page?
Anomalies on this page are calculated against the 1961-1990 climatological baseline, which is the standard reference period used by the Met Office, NOAA, IPCC and most national climate services. Some panels also show the source-native 1901-2000 (NOAA) or 1991-2020 (WMO) baselines for verification. See Methodology & Sources for the full reference.
Which areas does the North America climate data cover?
The North America climate profile covers United States, Canada, Mexico, Cuba and surrounding areas. Aggregated from country snapshots - NOAA does not publish a NA continental series
How often is the North America climate update refreshed?
The North America climate update is refreshed monthly, typically a few days after the previous month closes and the upstream provider (Met Office HadUK-Grid, NOAA Climate at a Glance, Copernicus ERA5 or the Global Carbon Project) publishes its update. See the Climate Rankings for cross-region comparisons.
What counts as a Heatwave Day on the North America climate page?
Heatwave Days use the Warm Spell Duration Index (WSDI) - the WMO/ETCCDI-standard heatwave measure: days that are part of a run of 6 or more consecutive days above the local 90th-percentile temperature for that calendar day. The 90th-percentile threshold varies by time of year (a hot day in January is judged differently to one in July) but is fixed to the 1961-1990 baseline for every year shown - it does not shift as the climate warms, which is why Heatwave Days trend upward over time.
Does the North America climate page include frost and snow data?
Yes. Frost Days (days with a minimum temperature below 0°C, World Bank CCKP) and snow water-equivalent (GPCC) are shown alongside temperature and precipitation, each measured against the 1961-1990 baseline where a like-for-like historical comparison is available.
What major climate events has North America experienced?
Major climate events in North America include Hurricane Hattie, 1961; The Great Ice Storm, 1998; The Greenland ice sheet melt of July 2012; Hurricane Otto, 2016; Hurricane Dorian, 2019; Canada's record wildfire season, 2023; Hurricane Melissa, 2025. The Climate History panel on this page lists 58 sourced events and pattern shifts relevant to North America, the earliest from 1912 - 25 about North America itself and the rest global context such as volcanic eruptions and El Niño events. Each entry carries its own sources and can be searched, filtered to local events or by category, and sorted by date; scrolling the list moves a cursor across the chart above so you can see where each event falls in the record.
Where does the Climate History list for North America come from, and how is it checked?
It is a hand-reviewed register, not an automatic feed. Every entry is sourced, and each one records how it was verified - against this site's own data series, against a peer-reviewed paper, or against the public record of the event. The rest give global or national context shared with wider pages. Where a figure is narrower than it first appears, or a famous claim does not hold locally, the entry says so.
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