ERA5 almanac comparison — 8 years of real data
Outer Banks vs St. Barthélemy: weather in September
Outer Banks edges out St. Barthélemy for sun in September: 40% clear historically versus 13% (8-year ERA5 average, a 27-point gap). St. Barthélemy also sees measurably more rain than Outer Banks this month (56% vs 36% of days). Both are viable — Outer Banks is the safer bet.
Outer Banks
NC
- Clear days, September
- 40%
- Sample size
- n=240 days
- Avg high
- 78°F
- Early September (1st–15th)
- 38%
- Late September (16th–end)
- 43%
- Rain frequency
- 36% of days
St. Barthélemy
St Barthelemy
- Clear days, September
- 13%
- Sample size
- n=240 days
- Avg high
- 84°F
- Early September (1st–15th)
- 14%
- Late September (16th–end)
- 12%
- Rain frequency
- 56% of days
Frequently asked
Is Outer Banks or St. Barthélemy warmer in September?
St. Barthélemy runs warmer by day in September. Outer Banks averages highs of 78°F (highs n=240 days); St. Barthélemy averages highs of 84°F (highs n=240 days) (ERA5 2018–2025). Historical averages, not a forecast.
Does it rain more in Outer Banks or St. Barthélemy in September?
St. Barthélemy is measurably wetter than Outer Banks. Days with measurable rain: Outer Banks 36%, St. Barthélemy 56% (n=240 and n=240 days). ERA5 2018–2025; historical, not a forecast.
Which is sunnier in September, Outer Banks or St. Barthélemy?
Outer Banks edges out St. Barthélemy for sun in September: 40% clear historically versus 13% (8-year ERA5 average, a 27-point gap). St. Barthélemy also sees measurably more rain than Outer Banks this month (56% vs 36% of days). Both are viable — Outer Banks is the safer bet.
Compare Outer Banks vs St. Barthélemy 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.