Updated October 2026
San Juan National Historic Site Weather by Month
San Juan National Historic Site is warmest in September, when the nearest NOAA climate station averages a high of 89°F and a low of 75°F, and coldest in February, with an average high of 83°F and an average low of 69°F. November is the wettest month, with about 9.8 inches of precipitation.
These figures are NOAA's 1991–2020 climate normals, the 30-year average for each calendar month, from the nearest long-record weather station, 4 miles from the park's reference point. A single station cannot describe a whole park: temperatures elsewhere in San Juan National Historic Site can differ from these, particularly with elevation.
Warmest month
Sep
89°F avg high
Coldest month
Feb
69°F avg low
Wettest month
Nov
9.8 in avg
Longest days
Jun
13.1 h of daylight
Average weather at San Juan by month
| Month | Avg high | Avg low | Precipitation | Daylight |
|---|---|---|---|---|
| January | 82°F | 70°F | 4.8 in | 11.0 h |
| February | 83°F | 69°F | 3.4 in | 11.4 h |
| March | 84°F | 70°F | 3.5 in | 11.9 h |
| April | 86°F | 72°F | 5.6 in | 12.4 h |
| May | 87°F | 74°F | 7.0 in | 12.9 h |
| June | 89°F | 76°F | 5.3 in | 13.1 h |
| July | 88°F | 76°F | 7.1 in | 13.0 h |
| August | 89°F | 76°F | 7.7 in | 12.6 h |
| September | 89°F | 75°F | 8.1 in | 12.1 h |
| October | 88°F | 75°F | 7.1 in | 11.6 h |
| November | 86°F | 73°F | 9.8 in | 11.1 h |
| December | 83°F | 71°F | 6.0 in | 10.9 h |
| Year total | 75.4 in |
NOAA 1991–2020 climate normals from station RQC00669415, 4 miles from the park's reference point. Daylight is the monthly average, computed from the park's latitude. Each month links to how crowded San Juan is at that time of year.
San Juan weather by season
Winter: December to February
Average highs hold near 83°F in all three months, with average lows near 70°F. Together the three months average 14.2 inches of precipitation, about 19% of the yearly total and less than in any other season. Daylight is at its shortest, about 10.9 hours in December.
Spring: March to May
Average highs climb from 84°F in March to 87°F in May, with average lows between 70°F and 74°F. Together the three months average 16.1 inches of precipitation, about 21% of the yearly total. Daylight lengthens from about 11.9 hours in March to 12.9 in May.
Summer: June to August
Average highs hold near 89°F in all three months, with average lows near 76°F. Together the three months average 20.1 inches of precipitation, about 27% of the yearly total. Daylight is at its longest, about 13.1 hours in June.
Fall: September to November
Average highs fall from 89°F in September to 86°F in November, with average lows near 74°F. Together the three months average 25 inches of precipitation, about 33% of the yearly total and more than in any other season. Daylight shortens from about 12.1 hours in September to 11.1 in November.
What the National Park Service says about the weather
Puerto Rico enjoys year round tropical climate. Winters are breeze and summers are mostly hot and humid. It rains all year long with a "dry" season in April. Temperatures range from 80's in the winter to 90's in the summer. The hurricane season starts in June and ends in November. On the longest day, June 22nd, the sun sets around 7 PM. On the shortest day, December 22nd, the sun sets around 4:30 PM.
Weather description courtesy of the National Park Service — official park site.
Today's forecast for San Juan
Averages describe a typical month, not this week. For current conditions and the seven-day outlook, the National Weather Service issues a forecast for the park's reference point at 18.47°N, 66.12°W. It covers that one spot, so other elevations in the park can differ from it, as they do from the averages above.
National Weather Service forecast for San Juan National Historic Site →
Weather and crowds together
September, the warmest month, is also the quietest, with about 0.5× the visitors of the park's average month. March is the busiest. To see those crowds set against the weather for all twelve months, read the best time to visit San Juan National Historic Site. For hotels, cabins and rentals close to the park, see where to stay near San Juan.
Where to stay near San Juan
Picked a month for San Juan National Historic Site? Compare hotels, cabins and vacation rentals near the park with live availability and prices.
Top-rated places to stay near San Juan
Prices for Oct 16–18, 4 adults. Change dates on the map below.
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Frequently Asked Questions
September is the warmest month at San Juan National Historic Site, with an average high of 89°F and an average low of 75°F. That is the 1991–2020 average at the nearest long-record NOAA station, 4 miles from the park's reference point. Temperatures inside the park can differ, particularly with elevation.
February is the coldest month at San Juan National Historic Site, with an average low of 69°F and an average high of 83°F, based on NOAA 1991–2020 climate normals.
November is the wettest month, with about 9.8 inches of precipitation. February is the driest, at about 3.4 inches. The station records about 75.4 inches of precipitation in an average year.
Daylight at San Juan National Historic Site runs from about 10.9 hours a day in December to about 13.1 hours in June, computed from the park's latitude.
Weather at nearby parks
91 mi away · warmest in August (90°F)
101 mi away · warmest in September (88°F)
106 mi away · warmest in September (88°F)
108 mi away · warmest in September (88°F)
Keep exploring
Sources: NOAA NCEI U.S. Climate Normals 1991–2020 (station RQC00669415), daylight computed from latitude, weather description from the National Park Service, crowd levels from National Park Service Visitor Use Statistics (1979–2025). Updated 2026-10-11. Lodging results are provided by Stay22; WhenToVisitParks may earn a commission from bookings, at no extra cost to you.