The best time to visit Costa Rica is Dec–Mar. Month by month, the verdicts rate Dec–Feb as comfortable on both daytime heat and rainfall — 3 months in all.
Summer wet season
| Month | High °C | High °F | Rainy days | Verdict |
|---|---|---|---|---|
| January | 28.0 | 82 | 23% | Go |
| February | 29.5 | 85 | 19% | Go |
| March | 31.3 | 88 | 18% | Fair |
| April | 31.3 | 88 | 36% | Fair |
| May | 28.9 | 84 | 69% | Too wet |
| June | 27.1 | 81 | 76% | Too wet |
| July | 27.1 | 81 | 69% | Too wet |
| August | 27.0 | 81 | 73% | Too wet |
| September | 26.4 | 80 | 81% | Too wet |
| October | 25.7 | 78 | 80% | Too wet |
| November | 26.3 | 79 | 65% | Too wet |
| December | 27.1 | 81 | 37% | Go |
Verdict combines mean daytime high with rainy-day frequency. “Rainy days” is the share of days in the month with at least 1 mm of rain.
March is the driest month, with rain on 18% of days and daytime highs near 31.3°C (88°F). September is the wettest, at 81%. The warmest month is March at 31.3°C (88°F); the coolest is October at 25.7°C (78°F). The record rules out too wet in May–Nov.