Puerto Rico Climate – July 2026 Update
Top 5 Cities: San Juan, Bayamón, Carolina, Ponce, and Caguas
Summary
Puerto Rico recorded its 4th warmest May to July on record, driven by steady heat that culminated in a scorching month. Average temperatures reached 27.51°C, making it the 3rd warmest July in 87 years of record-keeping at 1.1°C above the 1961–1990 baseline. The unrelenting heat and severe lack of rainfall have triggered a widespread water crisis across the island, forcing emergency water rationing for over 180,000 residents in major urban centres including San Juan. This acute drying aligns with the influence of a moderate El Niño in the tropical Pacific, which is forecast to peak at Very Strong in Oct-Dec on the live tracker at ENSO, with dry conditions expected to persist into autumn.
This month in numbers
The recent three-month period from May to July averaged 26.87°C, running 1°C above the long-term reference level as the 4th warmest such period since records began in 1940. July itself registered an average temperature of 27.51°C, placing it 3rd highest on record, trailing only the record set in 2024 (27.94°C). Globally, land temperatures during the month sat 1.6°C above the baseline, marking the 3rd warmest July on record worldwide, while the May to July global land average ranked 2nd warmest. On the island, the long-term warming trend now stands at +0.71°C, building upon 2025 being the 3rd warmest full year on record at 25.89°C.
What changed
The transition into summer brought an intensifying stretch of heat and dryness across the island, with temperatures rising steadily from 24.93°C in April to 26.11°C in May, 26.99°C in June, and 27.51°C in July. While Puerto Rico ranked 170th out of 232 regions globally for its single-month anomaly (+1.12°C), the compounding effect of months of below-average precipitation has led to severe hydrological deficits. Across the Caribbean, persistent high-pressure atmospheric patterns have exacerbated local drying, causing reservoir levels to plummet and triggering hundreds of brush fires in rural and coastal areas.
What’s driving change?
The primary atmospheric driver influencing the region is ENSO, with the Pacific currently in a moderate El Niño phase with a Relative Niño Index anomaly of +0.98°C. Historically, El Niño events create increased wind shear across the Caribbean basin that suppresses tropical storm development while favouring drier conditions across Puerto Rico with roughly 60% reliability. This suppressed rainfall, combined with baseline atmospheric warming driven by global climate change where , has allowed dry soils to bake under relentless summer sunlight. Readers can monitor ocean anomalies and probability forecasts on our live tracker at ENSO.
Looking ahead
Seasonal climate models indicate that drought conditions and unseasonable warmth are likely to persist through autumn as El Niño continues to strengthen in the tropical Pacific.
Generated by Gemini from climate data and web sources
At a Glance
Temperature – Average
Climate Map – Global
Source: NOAA Climate at a Glance (countries & continents) · Met Office (UK) · US states & climate regions. Anomalies are vs the 1961–1990 baseline. See methodology.
Typical Climate – Puerto Rico
Köppen Af · TropicalPuerto Rico has a tropical climate (Köppen Af: Tropical rainforest), with little variation in temperature or rainfall across the year. August is typically the warmest month, averaging 27.2°C, while February is the coldest at 24.2°C. Annual precipitation averages around 1703mm, spread fairly evenly across the year.
Monthly climate normals (2016–2025) - bar colour and height show average temperature, the shaded area shows average monthly precipitation.
Data: Our World in Data / NOAA (precipitation: GPCC (DWD); frost: World Bank CCKP).
Long-Term Trends
Combined Timeline – Puerto Rico
Precipitation, Sunshine, Frost and Snow are converted to standard deviations from their own average so they can share an axis with Temperature.
Data: Our World in Data / NOAA (precipitation: GPCC (DWD); frost: World Bank CCKP).
Heatwave Days – Puerto Rico
Warm Spell Duration Index (WSDI) - days in a 6+ day run above the local 90th-percentile temperature for that time of year.
Data: World Bank Climate Change Knowledge Portal (ERA5-derived). Refreshed roughly 1-2x/year, ~7-8 months behind present.
Year-on-Year Trends
The 4byo Climate Helix – Puerto Rico
Data: Our World in Data / NOAA (precipitation: GPCC (DWD); frost: World Bank CCKP).
Monthly Temperature – Puerto Rico
Latest month is provisional and may be revised by the data provider in the next update cycle.
Background lines show the last 40 years (plus the record year and its opposite, wherever they fall).
Data: Our World in Data / NOAA (precipitation: GPCC (DWD); frost: World Bank CCKP).
Records – Puerto Rico
Our World in Data / NOAA (precipitation: GPCC (DWD); frost: World Bank CCKP) - Anomalies vs 1901-2000 mean
Shifting Seasons
Weakly seasonalKöppen Af · TropicalPuerto Rico is weakly seasonal - temperature barely changes across the year (3.0°C range) and rainfall is fairly even. The clearest climate signal here is overall warming: monthly temperature has risen in every month.
Baseline vs recent monthly temperature climatology. Biggest warming: Oct (+1.3°C).
Data: Our World in Data / NOAA (precipitation: GPCC (DWD); frost: World Bank CCKP).
Climate Systems
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Emissions & Energy
Explore
Explore Climate Data
Data Sources
Data Sources for Puerto Rico
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.
Country-level temperature anomaly, sourced from Copernicus ERA5 and Hadley HadCRUT5.
Annual country and global CO₂ emissions, from the Global Carbon Project.
Monthly rainfall - Global Precipitation Climatology Centre (DWD) preferred, World Bank CCKP/CRU TS fallback where GPCC lacks direct coverage.
Frost Days and Heatwave Days (Warm Spell Duration Index), ERA5-derived. World Bank Climate Change Knowledge Portal.
Monthly snow water-equivalent, Global Precipitation Climatology Centre (DWD).
FAQs
FAQs
How is the climate in Puerto Rico changing?
Puerto Rico 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.
What is the climate like in Puerto Rico?
Puerto Rico has a tropical climate (Köppen Af: Tropical rainforest), with little variation in temperature or rainfall across the year. August is typically the warmest month, averaging 27.2°C, while February is the coldest at 24.2°C. Annual precipitation averages around 1703mm, spread fairly evenly across the year.
Where does the climate data for Puerto Rico come from?
Climate data for Puerto Rico 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 Puerto Rico climate data cover?
The Puerto Rico climate profile covers San Juan, Bayamón, Carolina, Ponce and surrounding areas. Temperature, rainfall and emissions data for Puerto Rico
How often is the Puerto Rico climate update refreshed?
The Puerto Rico 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 Puerto Rico 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 Puerto Rico 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.