September · United States
Best time to visit Key West in September Weather, crowds & prices
Weather in Key West in September
Average temperature 30°C, 308 mm of rain, about 24 days with 6+ hours of sunshine and 76% humidity — based on the five most recent complete years of ERA5 data (2021–2025).
September score
6.2/10
Ranked #11 of 12 months
- Avg temp
- 30°C
- Rainfall
- 308 mm
- Humidity
- 76%
- Days with 6h+ sun
- 24
- Crowd Density
- Quiet / Uncrowded
- Average Expenses
- $ · Budget Friendly ($)
September in Key West scores 6.2/10 for beach and coastal travel - ranked #11 of 12. Expect around 30°C, 308 mm of rain, and roughly 24 days with 6+ hours of sunshine this month.
Conch pastel lanes at the end of Overseas Highway at their best in January-April.
September in Key West — workable with trade-offs
Days in September average 30°C (86°F) and humidity near 76% — front-load outdoor plans before the heat builds and treat the middle of the day as indoor time.
This is the year's wettest stretch at 308 mm, but with about 24 days with 6+ hours of sunshine it is not a total loss; an indoor fallback covers the risk.
That is 6.2/10 on the same scale — 11th of 12 months, versus 8.6/10 for the best month here.
Pack the lightest breathable clothing you own, a hat, and more water than feels necessary, a proper rain shell rather than an umbrella.
Budget for low-season pricing, and crowds are light for this destination.
If your dates are flexible, March is materially better in Key West — 2.4 points higher on the same scale.
Frequently asked
- What is the weather like in Key West in September?
- In September, Key West averages 30°C, 308 mm of rain, and about 24 days with 6+ hours of sunshine. Its climate-comfort score is 6.2/10.
- Is September a good time to visit Key West?
- September earns a 6.2/10 climate-comfort score. Use the year-round chart to weigh the weather against your budget and crowd preferences.
- How much does it rain in Key West in September?
- Expect about 308 mm of rain in September. Average humidity is 76% and there are about 24 days with 6+ hours of sunshine.
Curated in Key West
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Key West, United States. Live activities and tours from GetYourGuide, matched to this destination.