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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 90°F, while the coldest is January averaging around 63°F at night. Precipitation totals about 46 inches a year and is strongly seasonal — September alone averages 8.2 inches while March barely receives 1.41 inches.
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 (°F) | 75 | 77 | 79 | 83 | 86 | 88 | 90 | 90 | 88 | 85 | 81 | 77 |
| Avg temp (°F) | 69 | 70 | 73 | 77 | 80 | 82 | 84 | 84 | 83 | 80 | 75 | 72 |
| Avg low (°F) | 63 | 64 | 67 | 71 | 74 | 77 | 78 | 79 | 77 | 75 | 70 | 66 |
| Precipitation (in) | 2.0 | 2.0 | 1.4 | 2.2 | 3.7 | 4.8 | 4.5 | 6.1 | 8.2 | 6.0 | 3.3 | 2.2 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Avg high (°F) | 75 | 77 | 79 | 83 | 86 | 88 |
| Avg temp (°F) | 69 | 70 | 73 | 77 | 80 | 82 |
| Avg low (°F) | 63 | 64 | 67 | 71 | 74 | 77 |
| Precipitation (in) | 2.0 | 2.0 | 1.4 | 2.2 | 3.7 | 4.8 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Avg high (°F) | 90 | 90 | 88 | 85 | 81 | 77 |
| Avg temp (°F) | 84 | 84 | 83 | 80 | 75 | 72 |
| Avg low (°F) | 78 | 79 | 77 | 75 | 70 | 66 |
| Precipitation (in) | 4.5 | 6.1 | 8.2 | 6.0 | 3.3 | 2.2 |
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 ≥ 90°F (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 ≥ 90°F (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 ≥ 90°F (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.