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United StatesThe weather in September in Key West
It's hot in September in Key West with an average temperature of 32°C. Temperatures this month range from a low of 31°C to a high of 32°C. At night, you can expect temperatures between 26°C and 29°C.
Looking for sun? September isn’t a good month to be in Key West. The temperature is nice, but there’s too much chance of rain.
Average temperatures and precipitation
This chart shows the average daily maximum and minimum temperatures (in degrees Celsius) and precipitation (in millimeters) in September for Key West, Florida. A low precipitation value usually indicates little to no rainfall on that day in recent years, while a higher value suggests more frequent rainfall.
Temperature records
With 35°C in 2017, Key West reached the highest temperature in September over the past 10 years. The lowest daytime temperature in this month was 27°C in 2014. The extreme nighttime temperatures ranged from a lowest recorded value of 22°C to a highest value of 30°C.
Water temperature
The water temperature at Key West is 31°C this month. It’s really warm, perfect for a swim.
Rainfall amount
In September, there is an average of 190 mm of precipitation, spread over 19 days. The wind speed is around 3 Bft, mostly coming from the Southeast.
Daily weather in September for Key West
Click on any day in September to get detailed info about the usual weather on that day in Key West. Check out the historical temperatures and precipitation over the past 10 years on this day.
September weather comparison
| Key West | New York | |
|---|---|---|
| Average temperature | 32°C | 27°C |
| Max. temperature | 32°C | 31°C |
| Min. temperature | 26°C | -5°C |
| Total precipitation | 190 mm | 57 mm |
| Rainy days | 19 days | 9 days |
Start of September
The month of September starts in Key West with hot temps, averaging around 32°C during the day and nights around 28°C.
Mid September
By mid-September, daytime temps stay steady at around 32°C, with nights around 28°C. During this part of the month, you might see regular precipitation, but there will also be some sunny days.
End of September
By the end of September, the average daytime temperature in Key West is around 32°C, while nighttime temps are about 28°C. There’s a significant chance of many days with precipitation.
Find affordable trips to Key West
UV index
The UV index is a maximum of 9 this month. That's a very high value on the intensity scale of 1 to 11. Unprotected skin can burn within 10-15 minutes.
The hurricane season in Key West runs from June to November.
Check out the climate of Key West for all months and discover the best travel time
Temperature charts
These charts show the average temperatures in September in Key West, Florida. The temperatures are shown in degrees Celsius and are calculated based on data from the past 10 years.
Daily Temperature in September in Key West
Temperature in September in Key West over the years
Precipitation charts
These charts show the average amount of precipitation in September in Key West, Florida. Precipitation is always measured as water, even when it falls as snow or hail The amount of precipitation is displayed in millimeters, while snowfall is shown in centimeters.
Daily Precipitation in September in Key West
Total precipitation in September in Key West over the years
Daily UV index in September in Key West
This chart shows the average daily UV index in September in Key West, with the UV index ranging from 0 to a maximum of 11. The bottom of the chart shows the days of the month. Based on historical data, this chart provides an idea of the daily UV radiation levels you can expect.
Weather experiences in September in Key West
Have you been to Key West in September?
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Average weather in Key West by month
Click on a month below to see detailed weather info for Key West. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.