ERA5 almanac comparison — 8 years of real data
Costa Rica — Guanacaste vs Hilton Head: weather in August
Essentially a tie in August: Costa Rica — Guanacaste is 6% clear historically, Hilton Head is 9% clear (8-year ERA5 average) — within the noise. Avg high 88°F vs 86°F. Pick based on flight time or price, not weather — the weather won't decide this one for you.
Costa Rica — Guanacaste
Costa Rica
- Clear days, August
- 6%
- Sample size
- n=248 days
- Avg high
- 88°F
- Early August (1st–15th)
- 8%
- Late August (16th–end)
- 5%
- Rain frequency
- 71% of days
Hilton Head
SC
- Clear days, August
- 9%
- Sample size
- n=248 days
- Avg high
- 86°F
- Early August (1st–15th)
- 6%
- Late August (16th–end)
- 12%
- Rain frequency
- 66% of days
Frequently asked
Is Costa Rica — Guanacaste or Hilton Head warmer in August?
Costa Rica — Guanacaste runs warmer by day in August. Costa Rica — Guanacaste averages highs of 88°F (highs n=248 days); Hilton Head averages highs of 86°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 August?
Days with measurable rain: Costa Rica — Guanacaste 71%, Hilton Head 66% (n=248 and n=248 days). ERA5 2018–2025; historical, not a forecast.
Which is sunnier in August, Costa Rica — Guanacaste or Hilton Head?
Essentially a tie in August: Costa Rica — Guanacaste is 6% clear historically, Hilton Head is 9% clear (8-year ERA5 average) — within the noise. Avg high 88°F vs 86°F. Pick based on flight time or price, not weather — the weather won't decide this one for you.
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.