Key West in Summer
In summer (June, July and August), Key West sees average daytime highs around 84°F and overnight lows near 81°F, with 10.7 in of rain over about 42 wet days across the season. It is the warmest season of the year and the 2nd-wettest season.
Across summer, daytime highs hold fairly steady around 84°F. The sky is clear or mostly clear about 36% of the time across summer, and the air most often feels miserable.
Summer is Key West's weakest season of the year to visit on our travel score. Key West has little temperature swing across the year, so its calendar seasons blur — the season framing matters less here than for a place with four distinct seasons. For the whole year in context, see Key West's year-round climate.
- Avg daytime high
- 84°F
- warmest season of the year
- Avg overnight low
- 81°F
- Rainfall
- 10.7 in
- 42 wet days
- Avg wind
- 10 mph
- Travel score
- 5.3
- weakest season of the year
- Months
- Jun · Jul · Aug
Temperature in Key West in Summer
Across summer, daytime highs hold fairly steady around 84°F.
A typical summer day in Key West reaches about 84°F and drops to 81°F overnight. The warmest of the three months is August, the coolest June.
How summer really feels in Key West
Once humidity and wind are folded in, summer brings about 77 days that feel above 90°F and 0 that feel at or below 32°F.
The story in summer is heat — humidity pushes the afternoon "feels like" well above the raw temperature.
Key West weather by month
How the three summer months (June, July and August) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 73° / 69° | 1.5 | 5.7 | 10.6 | 7.8 |
| Feb | 73° / 70° | 1.2 | 4 | 11.1 | 8.1 |
| Mar | 74° / 71° | 1.0 | 4.2 | 11.8 | 8.4 |
| Apr | 77° / 74° | 1.5 | 4.5 | 12.6 | 8.3 |
| May | 80° / 77° | 2.6 | 7.9 | 13.2 | 7.3 |
| Jun | 83° / 80° | 4.1 | 12.7 | 13.5 | 5.7 |
| Jul | 84° / 81° | 2.5 | 12.9 | 13.4 | 5.3 |
| Aug | 84° / 81° | 4.1 | 16.1 | 12.9 | 4.8 |
| Sep | 83° / 80° | 5.4 | 17.7 | 12.2 | 4.7 |
| Oct | 81° / 78° | 4.6 | 12.7 | 11.4 | 6.2 |
| Nov | 77° / 74° | 1.5 | 5.8 | 10.8 | 7.8 |
| Dec | 75° / 71° | 1.3 | 5.1 | 10.5 | 8.0 |
Cloud cover in Summer
The sky is clear or mostly clear about 36% of the time across summer.
Chance of precipitation in Summer
Key West gets around 10.7 in of rain over 42 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels miserable — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 10 mph across summer.
Sunrise & sunset in Summer
Daylight runs from about 13 h 24 min in early June to 12 h 30 min by late August. The lit band spans sunrise to sunset each day.
Solar energy in Summer
Average shortwave solar energy reaching the ground each day across summer, about 6.5 kWh/m².
Hazard calendar for Key West
In summer, Key West overlaps its atlantic hurricane and rainy season season. The full year is below, with each hazard's peak months called out.
Key West sits in the Atlantic hurricane belt; the season peaks August–October.
Key West's rainy season runs May–October, when most of the year's rain falls.
Is summer a good time to visit Key West?
Our two travel scores rate summer for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
summer is a reasonable time to visit Key West for sightseeing. The water and warmth also suit a beach or pool day.
What to pack for Key West in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Key West sees daytime highs around 84°F and nights near 81°F. Pack light clothes, rain gear and sun protection. About 42 days see rain.
Sea temperature near Key West in Summer
The nearest coast averages about 85°F across summer — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea offshore is warmest in August at about 86°F and coldest in February near 73°F.
The water stays above 68°F all year — warm enough for a swim any month.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°F) | 73 | 73 | 74 | 77 | 80 | 83 | 85 | 86 | 85 | 83 | 78 | 75 |
| Comfort | Refreshing | Refreshing | Refreshing | Warm | Warm | Tropical | Tropical | Tropical | Tropical | Tropical | Warm | Warm |
| Sea temperature (°F) | Comfort | |
|---|---|---|
| Jan | 73 | Refreshing |
| Feb | 73 | Refreshing |
| Mar | 74 | Refreshing |
| Apr | 77 | Warm |
| May | 80 | Warm |
| Jun | 83 | Tropical |
| Jul | 85 | Tropical |
| Aug | 86 | Tropical |
| Sep | 85 | Tropical |
| Oct | 83 | Tropical |
| Nov | 78 | Warm |
| Dec | 75 | Warm |
UV index in Key West in Summer
Clear-sky midday UV across summer averages around 12 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Key West peaks around July 18 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 18 at about 5 (high).
The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 6 | 8 | 10 | 11 | 11 | 11 | 12 | 12 | 11 | 9 | 6 | 5 |
| Level | High | Very high | Very high | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Very high | High | High |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 6 | High |
| Feb | 8 | Very high |
| Mar | 10 | Very high |
| Apr | 11 | Extreme |
| May | 11 | Extreme |
| Jun | 11 | Extreme |
| Jul | 12 | Extreme |
| Aug | 12 | Extreme |
| Sep | 11 | Extreme |
| Oct | 9 | Very high |
| Nov | 6 | High |
| Dec | 5 | High |
Air quality in Key West in Summer
Average fine-particle pollution (PM2.5) through the year — so you can see where summer falls, not just the annual average.
Air quality in Key West is worst in July — around 18 µg/m³ PM2.5 (moderate), about 4.1× the cleanest month (December, 4 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 5 | 5 | 6 | 8 | 9 | 15 | 18 | 16 | 10 | 7 | 5 | 4 |
| Level | Good | Good | Good | Good | Good | Moderate | Moderate | Moderate | Good | Good | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 5 | Good |
| Feb | 5 | Good |
| Mar | 6 | Good |
| Apr | 8 | Good |
| May | 9 | Good |
| Jun | 15 | Moderate |
| Jul | 18 | Moderate |
| Aug | 16 | Moderate |
| Sep | 10 | Good |
| Oct | 7 | Good |
| Nov | 5 | Good |
| Dec | 4 | Good |
Where is Key West?
Key West sits at 24.6°N, 81.8°W, 3 ft above sea level, in United States. The nearest listed city is Marco Island, 96 mi away.
Topography around Key West
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Key West.
Within 2 miles, the terrain around Key West has only modest variations in elevation — a maximum elevation change of 39 ft around an average of 3 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 75 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 52 ft.
The land around Key West is covered by water (64%) and artificial surfaces (26%) within 2 miles, water (95%) within 10 miles, and water (98%) within 50 miles.
United States travel facts
- Power plugs
- Type A / B
- 120 V · 60 Hz
- Prices
- ≈ 100% of US
- price level, 2025
- GDP per capita
- $90,027
- 2025
- Happiness
- 6.8 / 10
- World Happiness, 2025
- Safe drinking water
- 98%
- of population, 2024
- Homicide rate
- 5.8
- per 100k, 2023
- Road deaths
- 12.7
- per 100k/yr, 2019
- Income group
- High
- World Bank
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Key West (24.5552°, -81.7816°, elevation 3 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google.