US Southwest Climate – April 2026 Update
Top States: Arizona, Colorado, New Mexico, and Utah
This month in numbers
The US Southwest region experienced a significant temperature anomaly of +7.38°C in the latest month compared to the 1961–1990 average. The 3-month anomaly stands at +5.27°C, and the 12-month rolling anomaly is +3.03°C. Globally, the US Southwest is currently experiencing exceptionally warm conditions, with all four of its constituent states ranking within the top 6 warmest regions worldwide for the latest month. In fact, 8 of the top 10 warmest regions globally for the latest month are US states.
Hottest & coolest US states
Within the US Southwest, Arizona /climate/us-arizona recorded the highest 1-month anomaly at +7.80°C, followed closely by Utah /climate/us-utah at +7.72°C and Colorado /climate/us-colorado at +7.21°C. New Mexico /climate/us-new-mexico also saw a substantial anomaly of +6.79°C. There were no unusually cool states within the US Southwest this month.
What's driving change?
The current ENSO state is Neutral, with an anomaly of -0.16°C versus 1991–2020 for January-March 2026. However, forecasts indicate a strong likelihood of El Niño developing in the coming months, with a 61% chance for May-July and a 79% chance for June-August /climate/enso. El Niño events typically have a warming effect on the global climate and can amplify extreme weather events such as heatwaves. The US Southwest has experienced an increase in extreme droughts during winter, a trend fueled by increasing ENSO impact. This region is particularly susceptible to the effects of , where dry soils cannot cool themselves through evaporation, leading to faster warming and the intensification of droughts into heatwaves.
Sources:
Generated by Gemini from climate data and web sources
Climate Map – USA
Source: NOAA Climate at a Glance — US states & climate regions (tavg, pcp). Anomalies are vs the 1961–1990 baseline (temperature) or 1991–2020 (rainfall). See methodology.
Temperature – Average
US Southwest – Monthly Temperature – All Years
Each line represents one year of monthly temperature in °C.
NOAA Climate at a Glance — regional tavg / pcp (monthly absolutes).
Shifting Seasons
Warm / cold seasonsHow spring and autumn have shifted in US Southwest. Spring is defined as the date monthly temperatures first rise above the long-term annual mean (10.8°C, from 1950–1979); autumn is the date they fall back below it. Temperature swings 23.3°C peak-to-peak across the year - a classic four-seasons rhythm.
Baseline vs recent monthly temperature climatology. Biggest warming: Dec (+2.0°C).
NOAA Climate at a Glance — regional tavg.
Rainfall & Rain Days – Totals
Member States (4)
Hottest & Coolest in US Southwest this Month
1-month anomaly vs 1961–1990 across the 4 members we cover. Click a name to open its profile.
Warmest
- 1.🇺🇸Arizona+7.80°C
- 2.🇺🇸Utah+7.72°C
- 3.🇺🇸Colorado+7.21°C
- 4.🇺🇸New Mexico+6.79°C
Coolest
- 1.🇺🇸New Mexico+6.79°C
- 2.🇺🇸Colorado+7.21°C
- 3.🇺🇸Utah+7.72°C
- 4.🇺🇸Arizona+7.80°C
Data Sources
- NOAA Climate at a Glance — Regional time series · NOAA code 107 · Open at NOAA
- Two-baseline model — comparison baseline 1961–1990; native baseline 1901–2000. Methodology →
Data Sources
Data Sources for US Southwest
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.
FAQs
FAQs
How is the climate in US Southwest changing?
US Southwest 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 trend rate is shown as °C per decade in the headline panel; you can also see the warmest and coolest years on file.
Where does the climate data for US Southwest come from?
Climate data for US Southwest comes from authoritative climate datasets including national meteorological services and peer-reviewed reanalyses, 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 US Southwest climate data cover?
The US Southwest climate profile covers Arizona, Colorado, New Mexico, Utah and surrounding areas. NOAA Southwest - AZ, CO, NM, UT
How often is the US Southwest climate update refreshed?
The US Southwest 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.