ERA5 almanac comparison — 8 years of real data
Jacksonville vs St. Augustine: weather in September
Jacksonville edges out St. Augustine for sun in September: 22% clear historically versus 17% (8-year ERA5 average, a 5-point gap). Both are viable — Jacksonville is the safer bet.
Jacksonville
FL
- Clear days, September
- 22%
- Sample size
- n=240 days
- Avg high
- 86°F
- Early September (1st–15th)
- 17%
- Late September (16th–end)
- 27%
- Rain frequency
- 58% of days
St. Augustine
FL
- Clear days, September
- 17%
- Sample size
- n=240 days
- Avg high
- 83°F
- Early September (1st–15th)
- 11%
- Late September (16th–end)
- 23%
- Rain frequency
- 64% of days
Frequently asked
Is Jacksonville or St. Augustine warmer in September?
Jacksonville runs warmer by day in September. Jacksonville averages highs of 86°F (highs n=240 days); St. Augustine averages highs of 83°F (highs n=240 days) (ERA5 2018–2025). Historical averages, not a forecast.
Does it rain more in Jacksonville or St. Augustine in September?
Days with measurable rain: Jacksonville 58%, St. Augustine 64% (n=240 and n=240 days). ERA5 2018–2025; historical, not a forecast.
Which is sunnier in September, Jacksonville or St. Augustine?
Jacksonville edges out St. Augustine for sun in September: 22% clear historically versus 17% (8-year ERA5 average, a 5-point gap). Both are viable — Jacksonville is the safer bet.
Compare Jacksonville vs St. Augustine 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.