September weather forecastSarnia, Canada
September
Weather in September
September, the first month of the autumn in Sarnia, is also an agreeable month, with an average temperature fluctuating between 21.8°C (71.2°F) and 12.9°C (55.2°F).Temperature
With the arrival of September, Sarnia experiences a modest decline in average high-temperatures, transitioning from a warm 25.3°C (77.5°F) in August to a pleasant 21.8°C (71.2°F). Sarnia throughout September, records an average low-temperature of 12.9°C (55.2°F).Humidity
The average relative humidity in September is 78%.Rainfall
In Sarnia, in September, it is raining for 12.4 days, with typically 35mm (1.38") of accumulated precipitation. Throughout the year, in Sarnia, there are 140.4 rainfall days, and 493mm (19.41") of precipitation is accumulated.Snowfall
In Sarnia, snow does not fall in June through September.Sea temperature
In Sarnia, the average seawater temperature in September is 20.8°C (69.4°F).Note: Most people do not find swimming enjoyable in water of 20.8°C (69.4°F). The task of controlling breathing becomes tougher as the temperature drops from 21°C (69.8°F) to 15°C (59°F).
Daylight
The average length of the day in September in Sarnia is 12h and 29min.On the first day of September in Sarnia, sunrise is at 6:54 am and sunset at 8:03 pm. On the last day of the month, sunrise is at 7:26 am and sunset at 7:12 pm EDT.
Sunshine
In September, the average sunshine is 8.2h.UV index
In Sarnia, Canada, the average daily maximum UV index in September is 3. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV rays for average individuals.Note: The maximum daily UV index of 3 in September interprets into the following recommendations:
Heed the precautions - Protecting the skin and eyes from damage is compulsory. Direct exposure to the Sun during its peak hours around mid-day should be minimized for safety. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Sarnia, Canada
- Average high temperature in September: 21.8°C
The warmest month (with the highest average high temperature) is July (25.8°C).
The month with the lowest average high temperature is January (-2.3°C).
- Average low temperature in September: 12.9°C
The month with the highest average low temperature is July (16.3°C).
The coldest month (with the lowest average low temperature) is January (-7.5°C).
Average pressure in September
Sarnia, Canada
- Average pressure in September: 1017.1mbar
The month with the highest atmospheric pressure is March (1018.8mbar).
The month with the lowest atmospheric pressure is June (1013.5mbar).
Average wind speed in September
Sarnia, Canada
- Average wind speed in September: 12.7km/h
The windiest month (with the highest average wind speed) is January (18.2km/h).
The calmest month (with the lowest average wind speed) is July (11km/h).
Average humidity in September
Sarnia, Canada
- Average humidity in September: 78%
The month with the highest relative humidity is February (86%).
The months with the lowest relative humidity are April and May (76%).
Average rainfall in September
Sarnia, Canada
- Average rainfall in September: 35mm
The wettest month (with the highest rainfall) is May (54mm).
The driest month (with the least rainfall) is February (28mm).
Average rainfall days in September
Sarnia, Canada
- Average rainfall days in September: 12.4 days
The month with the highest number of rainy days is May (15.7 days).
The month with the least rainy days is February (5.7 days).
Average snowfall in September
Sarnia, Canada
- Average snowfall in September: 0mm
The month with the highest snowfall is February (99mm).
The months with the least snowfall are June, July, August and September (0mm).
Average snowfall days in September
Sarnia, Canada
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (14.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average sea temperature in September
Sarnia, Canada
- Average sea temperature in September: 20.8°C
The best month for swimming (with the highest average sea temperature) is August (23.2°C).
The coldest months (with the lowest average sea temperature) are February and March (0.3°C).
Average daylight in September /
Average sunshine in September
Sarnia, 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 12min
The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 2h and 54min).
Average sunshine days in September
Sarnia, Canada
- Average sunshine days in September: 15 days
The month with the most sunshine days is November (15.2 days).
The month with the least sunshine days is February (11.3 days).
Average UV index in September
Sarnia, Canada
- Average UV index in September: 3
The months with the highest UV index are July and August (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Sarnia, Canada
- Average cloud cover in September: 35
The month with the most cloud cover is January (Cloud cover 70).
The month with the least cloud cover is July (Cloud cover 30).
Average visibility in September
Sarnia, Canada
- Average visibility in September: 9km
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (9km).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (9km).
