Het weer in Nationaal park Manuel Antonio in januari

January opens the hottest, driest run of the Costa Rican year, with strong sun and lower humidity - and regulars still say to expect some rain most days, generally in the afternoon or at night. Our 22.2 precipitation days across 120.4mm is that, five millimetres a day, and one visitor's accounting is the clearest version: roughly eight hours of rain across a week, five of them after dark. Their weather apps had predicted rain daily. The date worth knowing is the 6th: the first days of January are peak holiday travel, and waiting until after about then means the Christmas crowds have gone and prices ease, though it stays high season. A light poncho and a small umbrella cover it. The record: 28.4C over 24.4C reading as 34C, a 28.9C sea and AQI 33.

Manuel Antonio's forum describes a fairly consistent August rhythm: clear, pleasant mornings, thunder rolling in over the mountains by early-to-mid afternoon, and rain arriving anywhere from 4 to 6pm that can continue into the night or clear up fast - though posters admitted the exact timing varies day to day and forecasts aren't reliable. The first half of the month tends to be somewhat less rainy than the back half. It's hot, humid and genuinely one of the wettest stretches of the year here, but the payoff repeated by multiple visitors is how lush and green everything gets - worth planning mornings for outdoor time and afternoons for a siesta.

Forum posters name February as the hottest month of the year here - typically 90-97F in the jungle, occasionally hotter right on the beach - and call it peak season for good reason, with humidity staying high (70%+) under blue skies dotted with big white clouds. Posters describe February as Manuel Antonio's driest month by local standards, though this is still a rainforest climate with real, near-daily rain even at its driest - the honest framing is 'least wet' rather than genuinely dry, since afternoon showers remain a common feature even in February, just shorter and less frequent than the region's true wet season (May-November). Posters are also emphatic that online weather forecasts for this area are essentially useless - conditions shift too fast and locally to trust anything beyond the broad seasonal pattern.