Measured, not vibes
Best Time to Visit San Juan
By measured weather comfort, the top months for San Juan are February, December, January — and RouteVerdict's editorial pick, which also weighs crowds and prices, is January, February, March, April, December. The table below is computed from ERA5 reanalysis data for 2020–2024, measured at San Juan (33 m elevation).
Month by month
San Juan weather and comfort, 2020–2024
| Month | Avg high | Wet days | Comfort | Season |
|---|---|---|---|---|
| January | 23.5°C / 74°F | 5.3 | 89 | Best |
| February | 23.9°C / 75°F | 4.2 | 91 | Best |
| March | 29°C / 84°F | 3.3 | 75 | |
| April | 31.4°C / 89°F | 6.7 | 56 | |
| May | 33.4°C / 92°F | 8.5 | 43 | |
| June | 35.2°C / 95°F | 7.8 | 34 | |
| July | 35.5°C / 96°F | 7.2 | 33 | |
| August | 36°C / 97°F | 7.3 | 30 | |
| September | 33.9°C / 93°F | 9 | 39 | |
| October | 31.5°C / 89°F | 6.3 | 56 | Shoulder |
| November | 26.7°C / 80°F | 5.8 | 81 | Shoulder |
| December | 24.8°C / 77°F | 3.7 | 91 | Best |
Comfort is RouteVerdict's 0–100 score: 100·exp(−(high−23)²/162) × (1 − min(0.35, wet days × 0.02)). The full method is on the methodology page. Weather data by Open-Meteo.com (ERA5, CC BY 4.0), 2020–2024 normals. Wet day = ≥1 mm precipitation.
What the seasons are actually like
Traveling to San Juan month by month
San Juan's comfort score peaks in February at 91.1, with an average high of 23.9°C and just 4.2 wet days, ahead of December's 90.8 and January's 89.3. Summer heat is severe: August averages 36°C, the hottest month, with comfort collapsing to just 30.1 — the lowest of the year. RouteVerdict's editorial pick spans January through April plus December, entirely avoiding the brutal May-through-November stretch.
FAQ
San Juan timing questions
What is the best month to visit San Juan?
By measured weather comfort (ERA5 2020–2024), the top months are February, December, and January, with February scoring highest. RouteVerdict's editorial pick is January, February, March, April, and December, which also weighs crowds, prices, and events.
What is the hottest month in San Juan?
August, with an average daily high of 36°C (97°F).
What is the rainiest month in San Juan?
September, averaging 9 days with at least 1 mm of precipitation.
When is shoulder season in San Juan?
November and October — the best-scoring months outside both the measured top three and RouteVerdict's editorial peak-season pick.
How hot does San Juan get in summer?
August averages 36°C, the hottest month, with comfort collapsing to just 30.1 — the lowest of the year.
What is San Juan's single best month for weather?
February, with an average high of 23.9°C, just 4.2 wet days, and a comfort score of 91.1 — the highest measured for any month.