Key West climate — normals and trends
Key West (United States) has a tropical savanna climate (Aw) under the Köppen-Geiger classification. Its mean annual temperature is 25.0 °C and it receives 819 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is August (28.0 °C on average) and the coldest is January (21.6 °C). Rainfall peaks in September.
Key West averages 0 frost days, 2 hot days (≥ 30 °C) and 124 rainy days per year.
Key West has warmed by +0.7 °C between 1940 and 2025, or +0.08 °C per decade. This trend is statistically significant.
The hottest day of the period reached 31.3 °C (on 10 August 2023) and the coldest 9.5 °C (on 24 January 2003).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
Key WestFlorida
- coords
- 24.56°, -81.78°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
25.0°C
Average daily high
25.8°C
Average daily low
24.1°C
Annual rainfall
819mm
Sunshine / day
11.0h
Mean relative humidity
78%
Average peak wind
27.1km/h
Seasonal range
6.4°C
Frost days (< 0 °C)
0 d/yr
Hot days (≥ 30 °C)
2 d/yr
Rainy days (≥ 1 mm)
124 d/yr
Annual snowfall
0.0 cm
Average feels-like high
28.4 °C
Average feels-like low
24.9 °C
Average peak gust
37.7 km/h
Tropical nights (≥ 20 °C)
330 d/yr
Solar radiation
19.8 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+0.7 °C
since 1940
+0.1 °C per decade · r² = 0.24 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
31.3 °C
10 August 2023
Coldest day
9.5 °C
24 January 2003
Wettest day
244 mm
26 August 2005
Windiest day
117.1 km/h
24 October 2005
Strongest gust
178.2 km/h
24 October 2005
Hottest feels-like
39.4 °C
9 August 2023
Coldest feels-like
2.2 °C
24 January 2003
Sunniest day
13.0 h
9 May 1940
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 21.7 °C | -0.9 °C | 41 mm | +3 mm |
| Feb | 23.8 °C | +1.1 °C | 29 mm | -5 mm |
| Mar | 24.0 °C | +0.5 °C | 9 mm | -23 mm |
| Apr | 25.2 °C | +0.4 °C | 16 mm | -17 mm |
| May | 27.6 °C | +1.3 °C | 28 mm | -30 mm |
| Jun | 28.6 °C | +0.8 °C | 177 mm | +67 mm |
| Jul | 29.2 °C | +0.6 °C | 56 mm | -12 mm |
| Aug | 29.8 °C | +1.0 °C | 102 mm | +4 mm |
| Sep | 28.9 °C | +0.6 °C | 192 mm | +47 mm |
| Oct | 27.7 °C | +0.7 °C | 154 mm | +34 mm |
| Nov | 25.1 °C | 0.0 °C | 29 mm | -18 mm |
| Dec | 24.3 °C | +0.7 °C | 53 mm | +17 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Key West?
Key West has a tropical savanna climate (Köppen Aw). Over 1940-2025, the average annual temperature is 25.0 °C and it receives 819 mm of precipitation per year.
What is the hottest day ever recorded in Key West?
The hottest day measured in Key West between 1940 and 2025 was 10 August 2023, reaching 31.3 °C.
What is the coldest day in Key West?
The coldest day measured in Key West between 1940 and 2025 was 24 January 2003, at 9.5 °C.
Does it snow in Key West?
Almost never: Key West sees virtually no snow, with about 0 frost days per year.
Has the climate of Key West warmed?
Yes: Key West warmed by +0.7 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Key West?
The wettest day measured in Key West between 1940 and 2025 was 26 August 2005, with 244 mm of rain in 24 hours.
What was the windiest day in Key West?
The windiest day measured in Key West between 1940 and 2025 was 24 October 2005, with winds reaching 117.1 km/h.
What is the warmest month in Key West?
The warmest month in Key West is August (28.0 °C on average); the coldest is January (21.6 °C).
How much does it rain in Key West?
Key West receives on average 819 mm of precipitation per year, spread over about 124 rainy days.
Is it sunny in Key West?
Key West gets on average 11.0 hours of sunshine per day, roughly 4,015 hours per year over 1940-2025.
Are there tropical nights in Key West?
Yes: Key West has on average 330 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Key West?
In Key West, between 1940 and 2025, the highest apparent temperature reached 39.4 °C on 9 August 2023, and the lowest was 2.2 °C on 24 January 2003.
Compare Key West with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Key West