Puerto Rico
4 cities
Climate overview
Puerto Rico sits at approximately 18°N in the Caribbean Sea as an unincorporated US territory (about 8,870 km² of land) comprising the main island of Puerto Rico, Vieques, Culebra, Mona, and numerous smaller islands and cays. The terrain features the rugged Cordillera Central mountain range rising to Cerro de Punta (1,338 m, the highest peak), narrow coastal plains along the Atlantic (north) and Caribbean (south) shores, El Yunque National Forest (the only tropical rainforest in the US National Forest System, receiving up to about 6,000 mm annually in its wettest areas) and mangrove and coral reef ecosystems along the coasts.
This geography produces a tropical maritime climate (Af/Am Köppen) characterized by warm temperatures year-round, high humidity, abundant rainfall especially on windward northern and eastern slopes, and vulnerability to Atlantic hurricane season from June through November.
San Juan sees highs of 28°C in January and 32°C in July, with nights of 22°C and 25°C, and 1,500 mm rainfall concentrated May–November. Ponce (south coast rain shadow) has highs of 31°C in January and 33°C in July, with nights of 17°C and 21°C, and 950 mm, drier with distinct wet and dry seasons. Mayagüez has highs of 29°C in January and 32°C in July. El Yunque peaks receive over 4,000 mm as Atlantic trade winds are forced up the mountains.
Puerto Rico endured severe Hurricane María (20 September 2017, a high-end Category 4 at landfall, about 2,975 deaths, $90 billion damage, the deadliest hurricane in Puerto Rico since 1899, causing the worst blackout in US history, which lasted months), Hurricane Fiona (18 September 2022, massive flooding and island-wide power failure), Hurricane Irma (September 2017, passing north of the island as a Category 5), the severe 2015 drought stressing agriculture and water supplies, rising seas that leave the coasts exposed to flooding, repeated coral bleaching during ocean heat extremes, and increasingly heavy rainstorms.
Our archive covers 4 Puerto Rican cities with daily ERA5 reanalysis data going back to 1940. Comparing the last decade against the 1940–1970 baseline, mean temperatures across these cities have risen by about 1.1°C.
How the climate has shifted in Puerto Rico
Average across 4 cities with full ERA5 coverage: 1940–1970 baseline vs the last decade (2016–2025).
- Annual mean temperature
- 25.8°C→26.8°C
- Days above 30°C per year
- 57 days→118 days+62
- Frost days per year
- 0 days→0 days+0
- Tropical nights (≥20°C) per year
- 364 nights→365 nights+1
Warmest year in the record so far: 2024.
What's unusual right now
From a snapshot of the world's largest cities updated each hour. Today's mean temperature compared with each city's long-term average for the same calendar date (ERA5 climatology, 1940 onward). Last 30 days uses each city's rolling daily-mean vs its monthly average. Not a global ranking.
Warmer than usual