September weather forecastHarefield, United Kingdom
September
Weather in September
September, the first month of the autumn in Harefield, is still a comfortable month, with an average temperature varying between 18.7°C (65.7°F) and 11.1°C (52°F).Temperature
The shift into September uncovers an average high-temperature of a comfortable 18.7°C (65.7°F), subtly different from the previous month. During September, Harefield consistently records a temperature low averaging a fresh 11.1°C (52°F).Humidity
In September, the average relative humidity is 78%.Rainfall
In Harefield, in September, it is raining for 8.9 days, with typically 14mm (0.55") of accumulated precipitation. In Harefield, during the entire year, the rain falls for 132.4 days and collects up to 214mm (8.43") of precipitation.Snowfall
In Harefield, snow does not fall in April through October.Daylight
In September, the average length of the day is 12h and 38min.On the first day of the month, sunrise is at 6:15 am and sunset at 7:48 pm. On the last day of September, sunrise is at 7:01 am and sunset at 6:41 pm BST.
Sunshine
In September, the average sunshine is 7.1h.UV index
The average daily maximum UV index in September in Harefield is 4. A UV Index reading of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for average individuals.Note: A maximum high UV index of 4 in September translates into the following recommendations:
Make use of precautions - It is urged to ward off sun damage. Solar radiation peaks around mid-day, so it's wise to limit exposure to the Sun at this time. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Harefield, United Kingdom
- Average high temperature in September: 18.7°C
The warmest month (with the highest average high temperature) is July (21.8°C).
The month with the lowest average high temperature is January (6.7°C).
- Average low temperature in September: 11.1°C
The month with the highest average low temperature is August (13.6°C).
The coldest month (with the lowest average low temperature) is January (1.8°C).
Average pressure in September
Harefield, United Kingdom
- Average pressure in September: 1016.9mbar
The month with the highest atmospheric pressure is September (1016.9mbar).
The month with the lowest atmospheric pressure is November (1010.5mbar).
Average wind speed in September
Harefield, United Kingdom
- Average wind speed in September: 12.8km/h
The windiest month (with the highest average wind speed) is February (17.6km/h).
The calmest month (with the lowest average wind speed) is July (12.7km/h).
Average humidity in September
Harefield, United Kingdom
- Average humidity in September: 78%
The month with the highest relative humidity is December (89%).
The month with the lowest relative humidity is August (74%).
Average rainfall in September
Harefield, United Kingdom
- Average rainfall in September: 14mm
The wettest month (with the highest rainfall) is December (25mm).
The driest month (with the least rainfall) is April (10mm).
Average rainfall days in September
Harefield, United Kingdom
- Average rainfall days in September: 8.9 days
The month with the highest number of rainy days is July (13.8 days).
The month with the least rainy days is September (8.9 days).
Average snowfall in September
Harefield, United Kingdom
- Average snowfall in September: 0mm
The month with the highest snowfall is December (10mm).
The months with the least snowfall are April, May, June, July, August, September and October (0mm).
Average snowfall days in September
Harefield, United Kingdom
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (2.8 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Harefield, United Kingdom
- Average daylight in September: 12h and 36min
The month with the longest days is June (Average daylight: 16h and 36min).
The month with the shortest days is December (Average daylight: 7h and 54min).
- Average sunshine in September: 7h and 6min
The months with the most sunshine are July and August (Average sunshine: 8h and 0min).
The month with the least sunshine is February (Average sunshine: 3h and 42min).
Average sunshine days in September
Harefield, United Kingdom
- Average sunshine days in September: 18.4 days
The month with the most sunshine days is September (18.4 days).
The month with the least sunshine days is July (14 days).
Average UV index in September
Harefield, United Kingdom
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Harefield, United Kingdom
- Average cloud cover in September: 49
The months with the most cloud cover are February and November (Cloud cover 60).
The months with the least cloud cover are April and September (Cloud cover 49).
Average visibility in September
Harefield, United Kingdom
- Average visibility in September: 9km
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October and December (9km).
The month with the lowest visibility is November (8km).
