Key West, FL Climate & Monthly Averages

Florida, United States 🇺🇸 · tropical wet-and-dry climate
Annual avg
78°
Hottest month
August
Coldest month
January
Rainy days / yr
136
Sunshine
10.8 h/day
Right now: 86° and light rain - see live conditions

The climate of Key West

Key West records 136 wet days and 10.8 hours of daily sunshine in an average year. Temperatures follow a tropical wet-and-dry pattern, running 73°F (23°C) in January up to 86°F (30°C) in August.

Climate quick facts

  • Hottest month: August - highs near 86°F (30°C)
  • Coldest month: January - highs near 73°F (23°C)
  • Decade extremes (2015-2024): 89°F (32°C) high · 54°F (12°C) low
  • Wettest month: September (19 rainy days) · Sunniest: July (12.2 h sun/day)
  • Climate type: tropical wet-and-dry
  • Annual swing: 7°C between the average warmest and coolest month · day to night: 2°C
  • Average humidity: 78%

Temperatures through the year

Warmth peaks in August: highs of 86°F (30°C), lows of 82°F (28°C). January bottoms out at 73°F (23°C) in daylight, 69°F (20°C) after dark. Across the gridded 2015-2024 daily record, the highest daily maximum for this location was 89°F (32°C) and the lowest daily minimum 54°F (12°C). The wettest month is September (6.6 inches (168 mm) across 19 days) and the driest February.

Rain, sun and snow

Between the average August and the average January lie 7°C, a narrower spread than about 81% of the cities we track. July is the brightest month at 12.2 hours of sun a day, against an annual average of 10.8 - sunnier than 91% of the 3496 cities in our dataset.

How Key West compares

  • Afternoons run 2°C above the following night - a flatter daily curve than almost every other city we track.

Ranked against every city in our dataset, each measured on the same ten-year window.

Monthly climate table

Monthly averages for Key West based on 2015–2024 weather data.
MonthHighLow Rain daysPrecipitation SunshineHumidity
January 73° 69° 8 1.9 in 9.4 h/day 78%
February 74° 70° 6 1.4 in 10.3 h/day 79%
March 76° 73° 4 1.5 in 11.0 h/day 76%
April 78° 75° 6 1.6 in 12.1 h/day 76%
May 81° 78° 11 3.6 in 12.1 h/day 76%
June 83° 80° 16 5.5 in 11.3 h/day 79%
July 85° 82° 15 3.6 in 12.2 h/day 77%
August 86° 82° 18 5.1 in 11.5 h/day 77%
September 85° 81° 19 6.6 in 10.5 h/day 78%
October 82° 79° 16 5.0 in 10.0 h/day 77%
November 79° 76° 8 3.0 in 9.7 h/day 77%
December 75° 72° 7 2.6 in 9.3 h/day 80%

Key West month by month

Key West weather in January

January brings highs around 73°F (23°C), lows near 69°F (20°C), about 8 wet days - typically the coldest month of the year in Key West.

Key West weather in February

February brings highs around 74°F (23°C), lows near 70°F (21°C), about 6 wet days - typically the driest month of the year in Key West.

Key West weather in March

March brings highs around 76°F (24°C), lows near 73°F (23°C), about 4 wet days.

Key West weather in April

April brings highs around 78°F (26°C), lows near 75°F (24°C), about 6 wet days.

Key West weather in May

May brings highs around 81°F (27°C), lows near 78°F (25°C), about 11 wet days.

Key West weather in June

June brings highs around 83°F (29°C), lows near 80°F (27°C), about 16 wet days.

Key West weather in July

July brings highs around 85°F (30°C), lows near 82°F (28°C), about 15 wet days - typically the sunniest month of the year in Key West.

Key West weather in August

August brings highs around 86°F (30°C), lows near 82°F (28°C), about 18 wet days - typically the hottest month of the year in Key West.

Key West weather in September

September brings highs around 85°F (29°C), lows near 81°F (27°C), about 19 wet days - typically the wettest month of the year in Key West.

Key West weather in October

October brings highs around 82°F (28°C), lows near 79°F (26°C), about 16 wet days.

Key West weather in November

November brings highs around 79°F (26°C), lows near 76°F (24°C), about 8 wet days.

Key West weather in December

December brings highs around 75°F (24°C), lows near 72°F (22°C), about 7 wet days.

Seasons in Key West

March through May

March through May in Key West is mild and warm, with daytime highs averaging 78°F (26°C) and nights around 75°F (24°C); expect showers on roughly 22 days across the season. Daylight is generous - around 11.7 hours of sun a day.

June through August

Through June through August, Key West is hot: 85°F (29°C) by day, 81°F (27°C) after dark, and rain falls on around 49 of the 90 days. Daylight is generous - around 11.7 hours of sun a day. With the moisture factored in, afternoons feel hotter than the reading suggests - the humidity and dew point converter shows why.

September through November

September through November runs hot here - highs near 82°F (28°C), nights near 78°F (26°C), and rain falls on around 44 of the 90 days. Daylight is generous - around 10.1 hours of sun a day.

December through February

December through February brings comfortable warmth here - highs near 74°F (23°C), nights near 70°F (21°C), and expect showers on roughly 21 days across the season.

Climate questions, answered

How many rainy days does Key West get in a year?
About 136 days bring measurable precipitation, totalling 41.4 inches (1052 mm). That works out at roughly 7.7 mm on an average wet day.
What should I pack for Key West?
It depends on the month: August runs to 86°F (30°C) while January holds at 73°F (23°C). The full month-by-month breakdown is in the packing notes above.
How hot does Key West get in summer?
August averages 86°F (30°C). Hot afternoons happen but extremes are not the norm.
Is Key West warmer or cooler than most cities?
Its 78°F (26°C) annual average is warmer than 86% of the 3496 cities in our dataset, which are all measured on the same 2015-2024 basis.

Best time to visit Key West

December to April is the sweet spot for Key West - warm days, manageable rainfall and plenty of daylight line up. Expect 75°F (24°C) in the afternoon and around 6 days of rain in a typical month of it. For the same question asked the other way round, see where else is warm in December.

Pack for Key West with light clothing for the warm months, a compact umbrella or rain shell and moisture-wicking fabrics for the humidity. Note the gap between afternoon and night: August pairs 86°F (30°C) with 82°F (28°C).

Key West temperature records (2015-2024)

Highest recorded
89°
in August
Lowest recorded
54°
in January
Annual precipitation
41.4"
Snowy days / yr
0

Derived from ERA5 reanalysis data, 2015–2024. Official station records may differ.