ERA5 almanac comparison — 8 years of real data
Charleston vs Sea Island: weather in July
Essentially a tie in July: Charleston is 12% clear historically, Sea Island is 14% clear (8-year ERA5 average) — within the noise. Avg high 88°F vs 87°F. Pick based on flight time or price, not weather — the weather won't decide this one for you.
Charleston
SC
- Clear days, July
- 12%
- Sample size
- n=248 days
- Avg high
- 88°F
- Early July (1st–15th)
- 11%
- Late July (16th–end)
- 13%
- Rain frequency
- 61% of days
Sea Island
GA
- Clear days, July
- 14%
- Sample size
- n=248 days
- Avg high
- 87°F
- Early July (1st–15th)
- 12%
- Late July (16th–end)
- 16%
- Rain frequency
- 64% of days
Frequently asked
Is Charleston or Sea Island warmer in July?
Charleston runs warmer by day in July. Charleston averages highs of 88°F (highs n=248 days); Sea Island averages highs of 87°F (highs n=248 days) (ERA5 2018–2025). Historical averages, not a forecast.
Does it rain more in Charleston or Sea Island in July?
Days with measurable rain: Charleston 61%, Sea Island 64% (n=248 and n=248 days). ERA5 2018–2025; historical, not a forecast.
Which is sunnier in July, Charleston or Sea Island?
Essentially a tie in July: Charleston is 12% clear historically, Sea Island is 14% clear (8-year ERA5 average) — within the noise. Avg high 88°F vs 87°F. Pick based on flight time or price, not weather — the weather won't decide this one for you.
Compare Charleston vs Sea Island 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.