How warm is it in Key West in August?

Daytime highs averaged 30.3 °C, night-time lows 29.5 °C. The highest value of the past 10 years was 31.9 °C (7 Aug 2023), the lowest 27.2 °C (25 Aug 2017).

How often does it rain in Key West in August?

On average there were 22.2 rain days (at least 1 mm) with 204 mm of precipitation in total.

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Key West weather in August: temperature & rain

Photo: Juliancolton · Public domain

🇺🇸 Weather in Key West in August

This is what the weather in Key West (Florida, USA) was like in August over the years 2017–2026.

Key facts at a glance

Prevailing weather: Light rain

Avg. daytime high

30.3 °C

29.6 °C – 31.0 °C

Avg. night-time low

29.5 °C

28.9 °C – 30.1 °C

Avg. rain days in period

22.2

72 % of days · ≥ 1.0 mm

Avg. precipitation in period

204 mm

17.3 mm – 773 mm

Avg. cloud cover

61 %

This data source has no sunshine hours – average cloud cover is shown instead.

Avg. sea temperature

–

Sea temperature unavailable for today (daily limit).

Extremes: Highest temperature 31.9 °C (7 Aug 2023) · Lowest temperature 27.2 °C (25 Aug 2017) · Avg. daily peak wind 20 km/h

Weather mix of all days

16Sunny
45Partly cloudy
17Cloudy
120Light rain
102Rain

Summary

On average 30.3 °C during the day and 29.5 °C at night.
On average 22.2 rain days (Rain day = at least 1.0 mm of precipitation) with 204 mm of precipitation in total.
Prevailing weather: Light rain.
Warmest year: 2023 (avg. 31.0 °C), coolest: 2018 (avg. 29.6 °C).
Wettest year: 2024 (773 mm), driest: 2017 (17.3 mm).
Extremes: 31.9 °C on 7 Aug 2023 and 27.2 °C on 25 Aug 2017.

Overall values from all 10 years. How is this calculated?

Temperatures per year

Average over your travel period

Precipitation & rain days

Year by year

2026
Avg. max30.8°Avg. min29.9°
Rain days
21 Rain days
Precipitation
124 mm
Avg. cloud cover
–
Sea temperature
–
Max 31.2 °C · Min 29.1 °C
2025
Avg. max30.8°Avg. min29.8°
Rain days
25 Rain days
Precipitation
167 mm
Avg. cloud cover
52 % cloudy
Sea temperature
–
Max 31.9 °C · Min 28.6 °C
2024
Avg. max30.6°Avg. min29.7°
Rain days
31 Rain days
Precipitation
773 mm
Avg. cloud cover
66 % cloudy
Sea temperature
–
Max 31.3 °C · Min 28.9 °C
2023
Avg. max31.0°Avg. min30.1°
Rain days
27 Rain days
Precipitation
169 mm
Avg. cloud cover
61 % cloudy
Sea temperature
–
Max 31.9 °C · Min 28.6 °C
2022
Avg. max30.3°Avg. min29.4°
Rain days
31 Rain days
Precipitation
424 mm
Avg. cloud cover
56 % cloudy
Sea temperature
–
Max 31.1 °C · Min 28.6 °C
2021
Avg. max29.9°Avg. min29.2°
Rain days
25 Rain days
Precipitation
206 mm
Avg. cloud cover
68 % cloudy
Sea temperature
–
Max 30.5 °C · Min 28.0 °C
2020
Avg. max30.1°Avg. min29.4°
Rain days
25 Rain days
Precipitation
90.4 mm
Avg. cloud cover
61 % cloudy
Sea temperature
–
Max 30.5 °C · Min 28.4 °C
2019
Avg. max30.1°Avg. min29.3°
Rain days
26 Rain days
Precipitation
45.2 mm
Avg. cloud cover
75 % cloudy
Sea temperature
–
Max 31.0 °C · Min 28.5 °C
2018
Avg. max29.6°Avg. min28.9°
Rain days
4 Rain days
Precipitation
20.3 mm
Avg. cloud cover
63 % cloudy
Sea temperature
–
Max 30.3 °C · Min 27.8 °C
2017
Avg. max29.9°Avg. min29.0°
Rain days
7 Rain days
Precipitation
17.3 mm
Avg. cloud cover
49 % cloudy
Sea temperature
–
Max 31.0 °C · Min 27.2 °C

Frequently asked questions

How warm is it in Key West in August?: Daytime highs averaged 30.3 °C, night-time lows 29.5 °C. The highest value of the past 10 years was 31.9 °C (7 Aug 2023), the lowest 27.2 °C (25 Aug 2017).
How often does it rain in Key West in August?: On average there were 22.2 rain days (at least 1 mm) with 204 mm of precipitation in total.

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Data sources

Weather data: Data obtained from the NASA Langley Research Center (LaRC) POWER Project funded through the NASA Earth Science/Applied Science Program
Reanalysis (weather model constrained by observations) on a coarse grid of about 50 km. Values represent a large area and can differ from local conditions, especially on islands, coasts and in mountains. Snow depth is the model value for the grid cell, not the depth on the slopes. No sunshine duration.
Reanalysis (weather model constrained by observations)
Reanalysis values represent a grid cell (approx. 25–50 km) and may differ from local measurements on coasts, islands and in mountains.
Sea temperature: MUR SST data were provided by JPL under support by NASA MEaSUREs program; accessed via NOAA CoastWatch ERDDAP
Daily multi-scale ultra-high resolution (≈ 1 km) analysis of satellite measurements (infrared, microwave) and in-situ data. Represents the foundation temperature below the daily warm surface layer. (Satellite and in-situ analysis)
Place search: Natural Earth (public domain) · GeoNames (CC BY 4.0) / OpenStreetMap (ODbL)