Key West, Florida climate: Normal weather by month, frost dates and records
Key West's normal year runs from 66°F January nights to 91°F August afternoons, with 40.4 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 26.1°C, January lows of 19°C, August highs of 33°C, 1,027 mm of precipitation a year.
- NOAA stationKey West International Airport
- Station IDUSW00012836
- Location24.55°N 81.75°W
- Elevation4 ft (1 m)
- Population25,240
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Key West.
- Jan 76° 66°
- Feb 77° 67°
- Mar 80° 69°
- Apr 83° 73°
- May 86° 76°
- Jun 89° 79°
- Jul 90° 81°
- Aug 91° 81°
- Sep 89° 79°
- Oct 86° 77°
- Nov 81° 72°
- Dec 78° 68°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Key West each month?
August is the warmest month, with normal highs of 91°F; January the coldest, with normal lows of 66°F. The most precipitation falls in September (7.24 in), the least in March (1.53 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 76°F | 66°F | 70.6°F | 1.83 | 7 | <1 | <1 | 10 h 50 min |
| February | 77°F | 67°F | 72.3°F | 1.54 | 5 | <1 | <1 | 11 h 20 min |
| March | 80°F | 69°F | 74.4°F | 1.53 | 5 | <1 | <1 | 12 h |
| April | 83°F | 73°F | 77.9°F | 2.07 | 5 | <1 | <1 | 12 h 40 min |
| May | 86°F | 76°F | 81.1°F | 3.12 | 8 | 1 | <1 | 13 h 20 min |
| June | 89°F | 79°F | 84.1°F | 4.23 | 11 | 7 | <1 | 13 h 40 min |
| July | 90°F | 81°F | 85.4°F | 3.63 | 12 | 18 | <1 | 13 h 30 min |
| August | 91°F | 81°F | 85.5°F | 5.37 | 15 | 20 | <1 | 13 h |
| September | 89°F | 79°F | 84.1°F | 7.24 | 16 | 10 | <1 | 12 h 20 min |
| October | 86°F | 77°F | 81.3°F | 5.67 | 12 | 1 | <1 | 11 h 40 min |
| November | 81°F | 72°F | 76.6°F | 2.05 | 6 | <1 | <1 | 11 h |
| December | 78°F | 68°F | 73.0°F | 2.16 | 6 | <1 | <1 | 10 h 40 min |
| Year (annual) | 84°F | 74°F | 78.9°F | 40.44 | 107 | 57 | <1 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 24°C | 19°C | 21.4°C | 46 mm |
| February | 25°C | 19°C | 22.4°C | 39 mm |
| March | 26°C | 21°C | 23.6°C | 39 mm |
| April | 28°C | 23°C | 25.5°C | 53 mm |
| May | 30°C | 25°C | 27.3°C | 79 mm |
| June | 32°C | 26°C | 28.9°C | 107 mm |
| July | 32°C | 27°C | 29.7°C | 92 mm |
| August | 33°C | 27°C | 29.7°C | 136 mm |
| September | 32°C | 26°C | 28.9°C | 184 mm |
| October | 30°C | 25°C | 27.4°C | 144 mm |
| November | 27°C | 22°C | 24.8°C | 52 mm |
| December | 25°C | 20°C | 22.8°C | 55 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00012836; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Key West?
Normal highs sit between 65°F and 85°F in January, February, March, April, November and December. Of those, April has the fewest days with rain (5).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USW00012836.
How hot and how cold does it get in Key West?
In a normal year in Key West, 57 days a year reach 90°F, nights almost never fall to freezing and 107 days bring measurable precipitation.
- Days at 90°F or more
- 57a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- fewer than 1a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 107a normal year
The highest temperature in Key West's official record (kept by the National Weather Service since 1872) is 97°F, on July 19, 1880; the lowest is 41°F, on January 12, 1886.
The wettest calendar year on that record is 1969, with 62.92 in.
Source: NOAA NCEI 1991-2020 annual normals, station USW00012836; records: ACIS (NOAA Regional Climate Centers), NWS threaded record EYWthr. Records use complete months only; a month missing more than three days is left out.
How humid and windy is Key West, and how clear are its skies?
The summer (June-August) dew point averages 75°F. The muggiest month is August, with an average dew point of 75°F, above the 65°F at which most people call the air sticky; the driest air comes in January (62°F). October is the windiest month (10.9 mph on average), and March has the most clear or nearly clear hours (73%).
| Month | Dew point | Humidity | Afternoon humidity | Wind | Clear or few clouds | Overcast |
|---|---|---|---|---|---|---|
| January | 62°F | 77% | 69% | 10.5 mph | 65% | 13% |
| February | 64°F | 75% | 66% | 10.7 mph | 69% | 10% |
| March | 66°F | 73% | 65% | 10.8 mph | 73% | 7% |
| April | 69°F | 72% | 66% | 10.8 mph | 72% | 6% |
| May | 73°F | 75% | 68% | 9.2 mph | 66% | 7% |
| June | 75°F | 74% | 67% | 8.9 mph | 68% | 6% |
| July | 75°F | 72% | 66% | 8.5 mph | 70% | 5% |
| August | 75°F | 74% | 69% | 8.6 mph | 67% | 6% |
| September | 75°F | 76% | 71% | 9.2 mph | 63% | 10% |
| October | 69°F | 74% | 67% | 10.9 mph | 67% | 9% |
| November | 66°F | 76% | 69% | 10.4 mph | 66% | 11% |
| December | 64°F | 78% | 71% | 10.4 mph | 61% | 14% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00012836. Monthly averages of all hours; afternoon humidity at 3 p.m. local standard time; sky as the share of hours NOAA's observations rate clear or few clouds (a dash where NOAA publishes no sky value).
How sunny is Key West?
Over a year 85% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Key West, 5.4 kWh per square metre a day. April is the sunniest month (90%) and January the cloudiest (81%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 81% | 3.9 |
| February | 85% | 4.8 |
| March | 89% | 5.9 |
| April | 90% | 6.6 |
| May | 88% | 6.7 |
| June | 83% | 6.3 |
| July | 85% | 6.3 |
| August | 85% | 6.1 |
| September | 82% | 5.4 |
| October | 84% | 4.8 |
| November | 84% | 4.1 |
| December | 83% | 3.6 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Key West need?
A normal year in Key West brings 47 heating degree days, 99% fewer than the median U.S. place (5,373), and 5,119 cooling degree days, 5.6 times the median (908). No month reaches 300 heating degree days. For gardens and crops, NOAA counts 10,548 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 22 | 197 |
| February | 11 | 214 |
| March | 4 | 297 |
| April | 0 | 386 |
| May | 0 | 501 |
| June | 0 | 572 |
| July | 0 | 632 |
| August | 0 | 637 |
| September | 0 | 573 |
| October | 0 | 505 |
| November | 0 | 348 |
| December | 10 | 258 |
| Year (annual) | 47 | 5,119 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00012836. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has Key West been warmer than normal lately?
2025 averaged 79.0°F, 0.1°F above the 1991-2020 normal of 78.9°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 78.8°F | −0.1°F | 30.43 |
| 2022 | 79.0°F | +0.1°F | 39.54 |
| 2023 | 80.6°F | +1.7°F | 37.02 |
| 2024 | 79.7°F | +0.8°F | 49.13 |
| 2025 | 79.0°F | +0.1°F | 39.78 |
Source: observed years: ACIS, station USW00012836. A year counts only with all twelve months complete.
How does Key West's climate compare?
Key West is warmer than 105 of the other 105 places with their own NOAA record in Florida, and wetter than 2. Across the 7,247 U.S. stations with normals, its annual mean of 78.9°F is warmer than 100%.
In the Köppen classification computed from these normals, Key West is Aw: tropical savanna. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Key West share this climate record?
2 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Stock Island, FL4,724 people · 1 mi NE
- Big Coppitt Key, FL3,333 people · 7 mi E
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
What do Key West's other NOAA stations record?
One more NOAA station keeps 1991-2020 normals in or near Key West. This page uses Key West International Airport; the other differs by site and elevation:
| Station | From this station | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Key West Naval Air Station USW00012850 | 5 mi NE | 6 ft | 78.8°F | 66°F | 90°F | 43.6 | 0 | – |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Key West's climate
What is the coldest month in Key West?
January, with a normal high of 76°F and a normal low of 66°F. The warmest is August (91°F by day, 81°F at night).
Does it snow in Key West?
Rarely. NOAA publishes no 1991-2020 snowfall normal for Key West's NOAA station; Key West's own co-op station Key West Naval Air Station records 0 inches of snow in a normal year.
What is the rainiest month in Key West?
September, with 7.24 in of precipitation in a normal year; the driest is March with 1.53 in.
What plant hardiness zone is Key West in?
The USDA's 2023 map puts Key West in zone 11b in ZIP code 33040.
Nearby and next
- Florida climateThe statewide normals and every place in the state
- Key W Weather Office, FL2 miles from this station, 77.3°F a year
- Bahia Honda State Park, FL30 miles from this station, 77.6°F a year
- Marathon, FL45 miles from this station, 78.8°F a year
- Curry Hammock State Park, FL50 miles from this station, 77.8°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made