ERA5 almanac comparison — 8 years of real data
Cancún vs Miami: weather in September
Essentially a tie in September: Cancún is 5% clear historically, Miami is 4% clear (8-year ERA5 average) — within the noise. Avg high 88°F vs 86°F. Pick based on flight time or price, not weather — the weather won't decide this one for you.
Cancún
Mexico
- Clear days, September
- 5%
- Sample size
- n=240 days
- Avg high
- 88°F
- Early September (1st–15th)
- 5%
- Late September (16th–end)
- 5%
- Rain frequency
- 71% of days
Miami
FL
- Clear days, September
- 4%
- Sample size
- n=240 days
- Avg high
- 86°F
- Early September (1st–15th)
- 5%
- Late September (16th–end)
- 4%
- Rain frequency
- 80% of days
Frequently asked
Is Cancún or Miami warmer in September?
Cancún runs warmer by day in September. Cancún averages highs of 88°F (highs n=240 days); Miami averages highs of 86°F (highs n=240 days) (ERA5 2018–2025). Historical averages, not a forecast.
Does it rain more in Cancún or Miami in September?
Days with measurable rain: Cancún 71%, Miami 80% (n=240 and n=240 days). ERA5 2018–2025; historical, not a forecast.
Which is sunnier in September, Cancún or Miami?
Essentially a tie in September: Cancún is 5% clear historically, Miami is 4% clear (8-year ERA5 average) — within the noise. Avg high 88°F vs 86°F. Pick based on flight time or price, not weather — the weather won't decide this one for you.
Compare Cancún vs Miami 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.