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Key West, Florida climate
Aw Tropical savanna (dry winter)
Key West has a mildly seasonal tropical climate (Tropical savanna (dry winter), Köppen Aw). The hottest month is August with an average daily high near 32°C, while the coldest is January averaging around 17°C at night. Precipitation totals about 1179 mm a year and is strongly seasonal — September alone averages 209 mm while March barely receives 36 mm.
Temperature & precipitation
Daily high–low temperature range with the monthly average, plus monthly precipitation · 1991–2020 normals · hover a month for the exact figuresClear vs cloudy days
Share of days each month that are clear, partly cloudy or cloudy · 1991–2020 · hover a month for the day countsKey West climate normals (1991–2020)
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 24 | 25 | 26 | 28 | 30 | 31 | 32 | 32 | 31 | 30 | 27 | 25 |
| Avg temp (°C) | 20 | 21 | 23 | 25 | 27 | 28 | 29 | 29 | 28 | 27 | 24 | 22 |
| Avg low (°C) | 17 | 18 | 19 | 22 | 23 | 25 | 25 | 26 | 25 | 24 | 21 | 19 |
| Precipitation (mm) | 51 | 50 | 36 | 55 | 94 | 122 | 114 | 156 | 209 | 153 | 83 | 56 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Avg high (°C) | 24 | 25 | 26 | 28 | 30 | 31 |
| Avg temp (°C) | 20 | 21 | 23 | 25 | 27 | 28 |
| Avg low (°C) | 17 | 18 | 19 | 22 | 23 | 25 |
| Precipitation (mm) | 51 | 50 | 36 | 55 | 94 | 122 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Avg high (°C) | 32 | 32 | 31 | 30 | 27 | 25 |
| Avg temp (°C) | 29 | 29 | 28 | 27 | 24 | 22 |
| Avg low (°C) | 25 | 26 | 25 | 24 | 21 | 19 |
| Precipitation (mm) | 114 | 156 | 209 | 153 | 83 | 56 |
How often — frequency of weather events
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 8 | 5 | 4 | 5 | 10 | 11 | 14 | 13 | 16 | 12 | 7 | 7 |
| Days with high ≥ 32°C (days) | — | — | — | — | 0.9 | 7 | 19 | 19 | 7 | 1 | 0.2 | — |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 8 | 5 | 4 | 5 | 10 | 11 |
| Days with high ≥ 32°C (days) | — | — | — | — | 0.9 | 7 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 14 | 13 | 16 | 12 | 7 | 7 |
| Days with high ≥ 32°C (days) | 19 | 19 | 7 | 1 | 0.2 | — |
Sky & atmosphere
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cloud cover (%) | 51 | 43 | 40 | 39 | 42 | 60 | 57 | 57 | 62 | 52 | 47 | 49 |
| Clear days (≤ 30% cloud) | 9 | 12 | 14 | 14 | 14 | 6 | 6 | 6 | 5 | 10 | 11 | 10 |
| Partly cloudy days (30–70%) | 12 | 10 | 11 | 11 | 10 | 11 | 14 | 14 | 12 | 11 | 11 | 13 |
| Cloudy days (≥ 70%) | 9 | 6 | 6 | 5 | 7 | 13 | 11 | 11 | 13 | 10 | 8 | 8 |
| Relative humidity (%) | 79 | 79 | 77 | 76 | 76 | 78 | 75 | 75 | 77 | 77 | 77 | 79 |
| Wind speed (mph) | 11.9 | 11.2 | 11.5 | 11.2 | 10.1 | 8.7 | 8.3 | 8.5 | 9.1 | 11.6 | 12.5 | 11.9 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 51 | 43 | 40 | 39 | 42 | 60 |
| Clear days (≤ 30% cloud) | 9 | 12 | 14 | 14 | 14 | 6 |
| Partly cloudy days (30–70%) | 12 | 10 | 11 | 11 | 10 | 11 |
| Cloudy days (≥ 70%) | 9 | 6 | 6 | 5 | 7 | 13 |
| Relative humidity (%) | 79 | 79 | 77 | 76 | 76 | 78 |
| Wind speed (mph) | 11.9 | 11.2 | 11.5 | 11.2 | 10.1 | 8.7 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 57 | 57 | 62 | 52 | 47 | 49 |
| Clear days (≤ 30% cloud) | 6 | 6 | 5 | 10 | 11 | 10 |
| Partly cloudy days (30–70%) | 14 | 14 | 12 | 11 | 11 | 13 |
| Cloudy days (≥ 70%) | 11 | 11 | 13 | 10 | 8 | 8 |
| Relative humidity (%) | 75 | 75 | 77 | 77 | 77 | 79 |
| Wind speed (mph) | 8.3 | 8.5 | 9.1 | 11.6 | 12.5 | 11.9 |
Methodology & sources
Temperature & precipitation — the official 1991–2020 climate normals from NOAA's U.S. Climate Normals, measured at Key W Wfo (NOAA GHCN station USC00084571), inside the city.
Cloud, humidity, wind & sunshine — modelled estimates from NASA POWER, NASA's satellite-and-reanalysis climatology. This is the standard global source for atmospheric variables, which are not measured at most weather stations.