September weather forecastLondon, Canada
September
Weather in September
September marks the shift from summer into autumn in London. The average high temperature drops significantly to 21.3°C (70.3°F) from August's highs, indicating summer's slow descent. Autumn hues punctuate the cityscape, painting a picturesque tableau against a golden sunset. Nature dresses in her Sunday best, announcing the arrival of fall. This period of transition has a certain poetic charm about it, with weather conditions perfectly balancing the receding warmth of summer against the gentle cool of the fall.Temperature
A subtle change in temperatures is noted as August gives way to September, with average highs reducing from a moderately hot 24.5°C (76.1°F) to an agreeable 21.3°C (70.3°F). September brings London a consistent average low-temperature of 11.7°C (53.1°F).Humidity
In September, the average relative humidity in London is 80%.Rainfall
In London, Canada, in September, during 10.6 rainfall days, 23mm (0.91") of precipitation is typically accumulated. Throughout the year, there are 128.1 rainfall days, and 346mm (13.62") of precipitation is accumulated.Snowfall
In London, snow does not fall in June through September.Daylight
The average length of the day in September is 12h and 29min.On the first day of the month, sunrise is at 6:50 am and sunset at 7:59 pm. On the last day of September, sunrise is at 7:21 am and sunset at 7:07 pm EDT.
Sunshine
In London, the average sunshine in September is 8.1h.UV index
The average daily maximum UV index in September is 3. A UV Index estimate of 3 to 5 represents a medium health hazard from exposure to the Sun's UV rays for ordinary individuals.Note: A daily maximum UV index of 3 in September translates into the following instructions:
Preventative actions are necessary - The mandate to avoid skin and eye damage is in place. Exposing oneself to the midday Sun can be harmful due to the strong UV radiation; limit your time outside. For holistic sun protection encompassing the eyes, ears, face, and neck, a wide-brim hat is key.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
London, Canada
- Average high temperature in September: 21.3°C
The warmest month (with the highest average high temperature) is July (25.5°C).
The month with the lowest average high temperature is January (-2.8°C).
- Average low temperature in September: 11.7°C
The month with the highest average low temperature is July (15.4°C).
The coldest months (with the lowest average low temperature) are January and February (-8.2°C).
Average pressure in September
London, Canada
- Average pressure in September: 1017.1mbar
The month with the highest atmospheric pressure is March (1018.7mbar).
The month with the lowest atmospheric pressure is June (1013.4mbar).
Average wind speed in September
London, Canada
- Average wind speed in September: 11.8km/h
The windiest month (with the highest average wind speed) is January (17.9km/h).
The calmest month (with the lowest average wind speed) is July (10.4km/h).
Average humidity in September
London, Canada
- Average humidity in September: 80%
The months with the highest relative humidity are January and February (88%).
The months with the lowest relative humidity are April and May (75%).
Average rainfall in September
London, Canada
- Average rainfall in September: 23mm
The wettest month (with the highest rainfall) is July (45mm).
The driest month (with the least rainfall) is March (20mm).
Average rainfall days in September
London, Canada
- Average rainfall days in September: 10.6 days
The month with the highest number of rainy days is May (14.1 days).
The months with the least rainy days are January and February (5.7 days).
Average snowfall in September
London, Canada
- Average snowfall in September: 0mm
The month with the highest snowfall is January (71mm).
The months with the least snowfall are June, July, August and September (0mm).
Average snowfall days in September
London, Canada
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (17.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
London, Canada
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in September: 8h and 6min
The month with the most sunshine is July (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 2h and 18min).
Average sunshine days in September
London, Canada
- Average sunshine days in September: 16.1 days
The month with the most sunshine days is September (16.1 days).
The month with the least sunshine days is January (9.3 days).
Average UV index in September
London, Canada
- Average UV index in September: 3
The months with the highest UV index are May, June, July and August (UV index 5).
The months with the lowest UV index are January, February and December (UV index 1).
Average cloud cover in September
London, Canada
- Average cloud cover in September: 38
The month with the most cloud cover is January (Cloud cover 76).
The month with the least cloud cover is July (Cloud cover 33).
Average visibility in September
London, Canada
- Average visibility in September: 9km
The months with the highest visibility are March, April, May, June, July, August, September, October, November and December (9km).
The months with the lowest visibility are January and February (8km).
