ERA5 almanac comparison — 8 years of real data
Costa Rica — Guanacaste vs Hilton Head: weather in January
Costa Rica — Guanacaste is the clear winner for sun in January: 79% of days historically clear versus just 0% in Hilton Head — a 79-point gap across 8 years of ERA5 data. Hilton Head also sees measurably more rain than Costa Rica — Guanacaste this month (27% vs 6% of days). This isn't close.
Costa Rica — Guanacaste
Costa Rica
- Clear days, January
- 79%
- Sample size
- n=248 days
- Avg high
- 91°F
- Early January (1st–15th)
- 72%
- Late January (16th–end)
- 85%
- Rain frequency
- 6% of days
Hilton Head
SC
- Clear days, January
- 0%
- Sample size
- n=248 days
- Avg high
- 58°F
- Early January (1st–15th)
- 1%
- Late January (16th–end)
- 0%
- Rain frequency
- 27% of days
Frequently asked
Is Costa Rica — Guanacaste or Hilton Head warmer in January?
Costa Rica — Guanacaste runs warmer by day in January. Costa Rica — Guanacaste averages highs of 91°F (highs n=248 days); Hilton Head averages highs of 58°F (highs n=248 days) (ERA5 2018–2025). Historical averages, not a forecast.
Does it rain more in Costa Rica — Guanacaste or Hilton Head in January?
Hilton Head is measurably wetter than Costa Rica — Guanacaste. Days with measurable rain: Costa Rica — Guanacaste 6%, Hilton Head 27% (n=248 and n=248 days). ERA5 2018–2025; historical, not a forecast.
Which is sunnier in January, Costa Rica — Guanacaste or Hilton Head?
Costa Rica — Guanacaste is the clear winner for sun in January: 79% of days historically clear versus just 0% in Hilton Head — a 79-point gap across 8 years of ERA5 data. Hilton Head also sees measurably more rain than Costa Rica — Guanacaste this month (27% vs 6% of days). This isn't close.
Compare Costa Rica — Guanacaste vs Hilton Head 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 forecast for any destination is on its own page and may differ from the long-run average. Data from Open-Meteo.