ERA5 almanac comparison — 8 years of real data
Amelia Island vs Cartagena: weather in September
Amelia Island edges out Cartagena for sun in September: 22% clear historically versus 1% (8-year ERA5 average, a 21-point gap). Both are viable — Amelia Island is the safer bet.
What you are reading: 8-year historical averages, not a forecast.
Either destination can still surprise you this specific September. For this
week’s actual forecast, each destination links to its live page below.
Amelia Island
FL
- Clear days, September
- 22%
- Sample size
- n=240 days
- Avg high
- 84°F
- Early September (1st–15th)
- 17%
- Late September (16th–end)
- 27%
- Rain frequency
- 62% of days
Cartagena
CO
- Clear days, September
- 1%
- Sample size
- n=240 days
- Avg high
- 86°F
- Early September (1st–15th)
- 2%
- Late September (16th–end)
- 0%
Compare Amelia Island vs Cartagena 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 7-day outlook for any destination is on its own page and may differ from the long-run average. Data from Open-Meteo.