ERA5 almanac comparison — 8 years of real data
Key West vs Palm Beach: weather in September
Key West edges out Palm Beach for sun in September: 11% clear historically versus 6% (8-year ERA5 average, a 5-point gap). Palm Beach also sees measurably more rain than Key West this month (79% vs 64% of days). Both are viable — Key West is the safer bet.
Key West
FL
- Clear days, September
- 11%
- Sample size
- n=240 days
- Avg high
- 85°F
- Early September (1st–15th)
- 14%
- Late September (16th–end)
- 8%
- Rain frequency
- 64% of days
Palm Beach
FL
- Clear days, September
- 6%
- Sample size
- n=240 days
- Avg high
- 86°F
- Early September (1st–15th)
- 5%
- Late September (16th–end)
- 8%
- Rain frequency
- 79% of days
Frequently asked
Is Key West or Palm Beach warmer in September?
Palm Beach runs warmer by day in September. Key West averages highs of 85°F (highs n=240 days); Palm Beach averages highs of 86°F (highs n=240 days) (ERA5 2018–2025). Historical averages, not a forecast.
Does it rain more in Key West or Palm Beach in September?
Palm Beach is measurably wetter than Key West. Days with measurable rain: Key West 64%, Palm Beach 79% (n=240 and n=240 days). ERA5 2018–2025; historical, not a forecast.
Which is sunnier in September, Key West or Palm Beach?
Key West edges out Palm Beach for sun in September: 11% clear historically versus 6% (8-year ERA5 average, a 5-point gap). Palm Beach also sees measurably more rain than Key West this month (79% vs 64% of days). Both are viable — Key West is the safer bet.
Compare Key West vs Palm Beach 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.