ERA5 almanac comparison — 8 years of real data
Houston vs Sea Island: weather in September
Essentially a tie in September: Houston is 30% clear historically, Sea Island is 32% clear (8-year ERA5 average) — within the noise. Avg high 88°F vs 83°F. Pick based on flight time or price, not weather — the weather won't decide this one for you.
Houston
TX
- Clear days, September
- 30%
- Sample size
- n=240 days
- Avg high
- 88°F
- Early September (1st–15th)
- 28%
- Late September (16th–end)
- 32%
- Rain frequency
- 50% of days
Sea Island
GA
- Clear days, September
- 32%
- Sample size
- n=240 days
- Avg high
- 83°F
- Early September (1st–15th)
- 26%
- Late September (16th–end)
- 37%
- Rain frequency
- 53% of days
Frequently asked
Is Houston or Sea Island warmer in September?
Houston runs warmer by day in September. Houston averages highs of 88°F (highs n=240 days); Sea Island averages highs of 83°F (highs n=240 days) (ERA5 2018–2025). Historical averages, not a forecast.
Does it rain more in Houston or Sea Island in September?
Days with measurable rain: Houston 50%, Sea Island 53% (n=240 and n=240 days). ERA5 2018–2025; historical, not a forecast.
Which is sunnier in September, Houston or Sea Island?
Essentially a tie in September: Houston is 30% clear historically, Sea Island is 32% clear (8-year ERA5 average) — within the noise. Avg high 88°F vs 83°F. Pick based on flight time or price, not weather — the weather won't decide this one for you.
Compare Houston 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.