ERA5 almanac comparison — 8 years of real data
Costa Rica — Manuel Antonio vs San Antonio: weather in December
Costa Rica — Manuel Antonio edges out San Antonio for sun in December: 22% clear historically versus 17% (8-year ERA5 average, a 5-point gap). Costa Rica — Manuel Antonio also sees measurably more rain than San Antonio this month (45% vs 21% of days). Both are viable — Costa Rica — Manuel Antonio is the safer bet.
Costa Rica — Manuel Antonio
CR
- Clear days, December
- 22%
- Sample size
- n=248 days
- Avg high
- 83°F
- Early December (1st–15th)
- 18%
- Late December (16th–end)
- 26%
- Rain frequency
- 45% of days
San Antonio
TX
- Clear days, December
- 17%
- Sample size
- n=248 days
- Avg high
- 68°F
- Early December (1st–15th)
- 20%
- Late December (16th–end)
- 14%
- Rain frequency
- 21% of days
Compare Costa Rica — Manuel Antonio vs San Antonio in another month
All percentages are historical averages from the ERA5 reanalysis via Open-Meteo, 8 full years (2018–2025). “Clear” means avg high ≥ 72 °F, precipitation < 1 mm, and a non-precipitation weather code. This is history, not a forecast. The live 7-day outlook for any destination is on its own page and may differ from the long-run average. Data from Open-Meteo.