Temperatures in September
It's hot in September in Heathrow with an average temperature of 32°C. Temperatures this month range from a low of 30°C to a high of 33°C. At night, you can expect temperatures between 23°C and 25°C.
Max and Min Temperatures per Day
This chart shows the daily maximum and minimum temperatures in degrees Celsius for Heathrow in September. The red line indicates the max temperatures, and the blue line shows the minimums.
Start of September
The month of September starts in Heathrow with hot temperatures, averaging around 33°C during the day and nights close to 25°C. Plenty of days with a chance of precipitation. Breezy clothes like shorts or a dress, plus a hat and sunglasses, are ideal.
Mid-September
By mid-September, the average daytime temperature drops to around 32°C, with nights close to 25°C. The chance of precipitation is high during this period. Breezy clothes like shorts or a dress, plus a hat and sunglasses, are ideal.
End of September
By the end of September, the average daytime temperature in Heathrow will be around 32°C, with nights close to 24°C. There’s a significant chance of many days with precipitation. Breezy clothes like shorts or a dress, plus a hat and sunglasses, are ideal.
Discover cheap trips to Heathrow 
Precipitation in September
In September, there is an average of 467 mm of precipitation, spread over 16 days. The wind speed is around 4 Bft, mostly coming from the Southeast.
Across the whole month, the average precipitation chance is 52% per day. Though it seems average, the weather’s variable. Some days have a lower chance of precipitation.
Precipitation Chance
This chart shows the daily precipitation chance (in percentages) in September for Heathrow. 0% means it never rained on that day in the past 10 years, and 100% means it rained every day. All values in between represent the average chance of precipitation on that day.
Heathrow in September |
London | ||
|---|---|---|---|
 Average Temperature |
32°C | 20°C | |
 High Temp |
33°C | 22°C | |
| Low Temp |
30°C | 17°C | |
 Total Precipitation |
467 mm | 44 mm | |
| Rainy Days |
16 days | 8 days | |
August
UV index
The UV index is a maximum of 8 this month. That's a very high value on the intensity scale of 1 to 11. Unprotected skin can burn within 10-15 minutes.
Is September a good time to visit Heathrow?
After some sun? Then September isn’t the best time to be in Heathrow. The temperature is pleasant, but there’s too much chance of rain this month.
The hurricane season in Heathrow runs from June to November.
Temperature records for Heathrow in September
With 35°C, Heathrow hit the highest temperature in the last 10 years in September 2019. The lowest daytime temperature in this month was 23°C in 2022. The extreme night temperatures ranged from a low of 17°C to a high of 28°C.
Check out the climate of Heathrow for all months and discover the best travel time
Plan your next holiday
Don’t miss the best holiday deals for Heathrow and see what our partners have for you.
Daily Temperature in September in Heathrow
This chart shows the average daily temperatures, both day and night, for each day in September in Heathrow, measured in degrees Celsius. The red line represents the maximum temperatures, while the blue line shows the minimums. The days of the month are displayed at the bottom of the chart. The data, based on historical observations, gives an overview of the average daily temperatures during this month.
Daily Precipitation in September in Heathrow
The chart below shows the average daily precipitation in September for Heathrow, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail. The days of the month are shown at the bottom of the chart.
A low average precipitation means that the chance of rain on that day is usually small, while a higher average suggests that rain is more likely. But it’s still an average, so each day can be different. Based on historical weather data for September, you can expect around 16 days of rain in Heathrow.
Daily UV Index in September in Heathrow
This chart shows the average daily UV index in September in Heathrow, 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.
Temperature in September in Heathrow Over the Years
This chart shows the average temperature in September in Heathrow, measured in degrees Celsius, over the past years.
Total Precipitation in September in Heathrow Over the Years
This chart shows the average precipitation in September in Heathrow, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail.
Daily climate in September for Heathrow
Click on a specific day in September for detailed info on the typical weather on that day in Heathrow. Check out the historical temperatures and precipitation over the past 10 years on this day.
Weather experiences in September in Heathrow
Have you been to Heathrow in September?
Share your weather experience in September in Heathrow.
Average Weather in Heathrow by Month
Click on a month below to see detailed weather info for Heathrow. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.
