Puerto Rico and the U.S. Virgin Islands Hazard Mitigation Plan Resource Page
U.S. Caribbean Climate Summary
Puerto Rico and the U.S. Virgin Islands are located in the subtropical Caribbean region. Puerto Rico comprises the main island and several smaller nearby islands, including Vieques, Culebra, Isla de Mona, Caja de Muertos, and Isla Desecheo. The major islands of the U.S. Virgin Islands are St. Thomas, St. Croix, and St. John. Surrounded by ocean on all sides, the islands experience warm and humid tropical conditions with minimal temperature variations between seasons. The temperate climate of San Juan, Puerto Rico, illustrates the tropical conditions of these islands. The annual average (1991–2020 normals) temperature is 81.0°F. Temperatures are generally cooler in January, with an average minimum temperature of 72.0°F and an average maximum temperature of 83.2°F, and warmer in August, with an average minimum temperature of 77.8°F and an average maximum temperature of 89.1°F.
Precipitation across Puerto Rico and the U.S. Virgin Islands varies seasonally, with wetter summers and relatively drier winters. The predominant synoptic influence on the islands’ climate is the North Atlantic subtropical high, which causes prevailing trade winds predominantly from the east and northeast. The east to west positioning of the Cordillera Central, where the highest elevation is 4,390 feet, provides a natural divide that separates Puerto Rico into two climatologically distinct regions. The northern two-thirds of Puerto Rico has a mostly humid climate, and the southern portion has a drier, semiarid climate. The northeast trade winds provide water vapor for precipitation along the northern coast and outlying islands, but passage over this mountain range removes moisture through precipitation, and the resulting downslope flow is drier. The U.S. Virgin Islands are not as high in elevation (the highest point is 1,555 feet on St. Thomas), but topographic effects on precipitation still occur, with the west (upwind) sides being wetter than the east (downwind) sides.
Key Points:
- Temperatures in Puerto Rico and the U.S. Virgin Islands have risen almost 2°F since 1950. Under a higher emissions pathway, historically unprecedented warming is projected during this century, including increases in extreme heat events.
- Future changes in total precipitation are uncertain, but extreme precipitation is projected to increase, with associated increases in the intensity and frequency of flooding.
- Since 1961, sea level has risen by 0.7 inches per decade at San Juan, Puerto Rico—a rate equal to the global sea level rise rate during the second half of the 20th century. Global sea level is projected to rise another 1–8 feet, and similar rises are projected for Puerto Rico and the U.S. Virgin Islands. Rising sea levels pose widespread and continuing threats to both natural and built environments in coastal communities.
- Hurricanes are a major threat to both Puerto Rico and the U.S. Virgin Islands. Hurricane rainfall rates, storm surge heights due to sea level rise, and the number of the strongest (Category 3, 4, and 5) hurricanes are all projected to increase in a warming climate.
From Runkle et al. (2022). Click here for the full report.
Puerto Rico Records
| High Temperature | Low Temperature | 24-hour Precipitation | 24-Hour Snowfall | 24-Hour Snow Depth | Tornadoes | Wettest Year |
|---|---|---|---|---|---|---|
| 104°F July 2, 1996 Mona Island |
40°F March 27, 1985 (Rincon) January 24, 1966 (San Sebastian) March 19, 1911 (Aibonito) |
23.75 in. October 7, 1985 Toro Negro Forest |
N/A | N/A | 1 | — |
U.S. Virgin Islands Records
| High Temperature | Low Temperature | 24-hour Precipitation | 24-Hour Snowfall | 24-Hour Snow Depth | Tornadoes | Wettest Year |
|---|---|---|---|---|---|---|
| 99°F June 23, 1996; August 4, 1994 (Charlotte Amalie, St. Thomas) July 31, 1988 (Cruz Bay, St. John) |
51°F January 31, 1954 Anna’s Hope, St. Croix |
20.00 in. September 4, 1979 Anna’s Hope, St. Croix |
N/A | N/A | — | — |
Temperature, precipitation, and snowfall records obtained from NOAA/NCEI’s State Climate Extremes Committee. Tornado information obtained from NOAA’s Storm Prediction Center (average annual number of tornadoes from 1995-2024).
Table last updated September 28, 2025.
U.S. Caribbean Resource Links
- Hazard Mitigation Plan for Puerto Rico (2021)
- Hazard Mitigation Plan for the U.S. Virgin Islands (2024)
- Central Office for Recovery, Reconstruction, and Resiliency (COR3)
- FEMA Resources for Puerto Rico
- FEMA Resources for the U.S. Virgin Islands
- Weather and Climate Observations for Puerto Rico (from the Puerto Rico Climatology Office)
- NOAA in the Caribbean
- National Weather Service San Juan (PR) Office
- Caribbean Collaborative Action Network (CCAN), a NOAA/CAP Team
- NOAA/NIDIS Drought Status Updates for Puerto Rico and the U.S. Virgin Islands
Have questions about these resources, or looking for something else? Contact Dr. Héctor Jiménez, Puerto Rico State Climatologist.