Key West Weather in August
Key West in August averages 32°C (90°F) during the day and 27°C (81°F) at night. Keep in mind that quite a bit of rainfall is expected this month.
Rainfall in Key West in August
This month experiences about 19 days of rain according to historical data, averaging 134 mm (5.3 in). Wet weather is a regular and significant part of this month. Frequent days of rain combined with high totals means proper waterproofs are worth packing.
Temperature in Key West in August
In August, Key West gets very high temperatures, with highs of 32°C (90°F). Nights cool to around 27°C (81°F). The hottest part of the day is usually in the afternoon, so lighter clothing can help you stay comfortable. At 27°C (81°F) overnight, the heat doesn't let up much after dark. If you're staying somewhere without air conditioning, a cold shower before bed and keeping the air moving can help. Expect some days to be hotter than these averages. Stay cool by wearing light clothing and drinking plenty of water throughout the day.
Sunshine in Key West in August
With approximately 309 hours of sunshine, the days are filled with clear skies. It makes it a perfect month for being outside.
Average water temperature in August
The water is 31°C (88°F) — very warm by most standards. Comfortable to swim in, but not particularly refreshing if you're looking to cool off.August in Key West has its charm. However, if you're seeking pleasant, dry and sunny weather, our weather planner can help you explore other destinations in the world.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United States of America, check out our Key West's climate page.
Key West Temperature in August
Min Temperature
27°C (81°F)
Max Temperature
32°C (90°F)
Water Temperature
31°C (88°F)
Chance of Rain
64%
Precipitation
134 mm (5.3 in)
Rainy days
19 days
Humidity
73%
Sunshine
309 hours
Percentage Sunshine
76%
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Key West typically stay consistent throughout August, with daily highs averaging around 32°C (90°F). Nights are warm, with lows around 27°C (81°F).
Average temperatures in August
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in August
Historical weather for Key West in August
Browse day-by-day weather records for Key West spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Key West historical weather extremes in August
Based on weather observations in Key West between 1976 and 2025, these are the recorded extremes during August.
- The hottest August day on record in Key West reached 36°C (97°F) (August 12, 2024).
- The coldest August day was on August 25, 2012, with a maximum of 27°C (81°F).
- Key West registered its coldest August night on August 5, 1985, with temperatures dropping to 22°C (72°F).
Best Places in the United States of America in August
Find out more about the weather in the United States of America and which places have the best travel conditions in this month. See all of the United States of America in August →
perfect weather
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What to Wear in Key West in August
Warm weather calls for comfortable, breathable clothing in August. Cotton t-shirts, shorts, light dresses, and sandals are perfect. You might still want a light layer for evenings or air-conditioned places (for example buses). High rain levels are expected, so pack waterproof gear and an umbrella or poncho. With water temperatures around 31°C (88°F), swimming conditions are excellent. Pack your swimsuit, goggles, and maybe some water shoes. And with plenty of sunshine hours, don’t forget sunglasses, sunscreen, and maybe a sun hat.What To Do in Key West in August
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United States of America, check out our Key West's climate page.
Temperature Rainfall Sunshine Humidity Water Temp
See the full Key West climate overview or explore weather in the United States of America.
