Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
During the shift to September, Saint Clair records a mild decrease in average high-temperature, moving from a moderately hot 79°F (26.1°C) in August to a pleasant 73°F (22.8°C). Saint Clair, during September nights, observes an average temperature of 53.6°F (12°C).Humidity
In Saint Clair, the average relative humidity in September is 80%.Rainfall
The month with the least rainfall is September, when the rain falls for 12.7 days and typically collects 2.09" (53mm) of precipitation.Snowfall
In Saint Clair, snow does not fall in June through September.Daylight
The average length of the day in September in Saint Clair is 12h and 27min.On the first day of the month, sunrise is at 6:32 am and sunset at 7:36 pm. On the last day of September, sunrise is at 7:01 am and sunset at 6:48 pm EDT.
Sunshine
In Saint Clair, the average sunshine in September is 8.8h.UV index
In September, the average daily maximum UV index in Saint Clair is 4. A UV Index value of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for the ordinary person.Note: The maximum daily UV index of 4 during September translates into the following directions:
Be vigilant - A duty to shield skin and eyes from injury exists. It's crucial to reduce time in the direct Sun around mid-day due to the intense solar radiation. Sun-related eye harm can be minimized with proper sunglasses offering UVA and UVB coverage.
Frequently asked questions
What are the temperatures in Saint Clair in September?
What is the average humidity in September in Saint Clair?
What is the driest month in Saint Clair?
How much does it rain in Saint Clair in September?
When it does not snow in Saint Clair?
Does it snow in Saint Clair in September?
What is the average length of the day in September in Saint Clair?
What time are sunrise and sunset in September in Saint Clair?
How long on average sun shines in September in Saint Clair?
What is the UV index intensity in September in Saint Clair?
Average temperature in September
Saint Clair, PA
- Average high temperature in September: 73°F
The warmest month (with the highest average high temperature) is July (81.5°F).
The month with the lowest average high temperature is January (32.5°F).
- Average low temperature in September: 53.6°F
The month with the highest average low temperature is July (61.3°F).
The coldest month (with the lowest average low temperature) is January (20.5°F).
Average pressure in September
Saint Clair, PA
- Average pressure in September: 30.06"Hg
The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in September
Saint Clair, PA
- Average wind speed in September: 5.5mph
The windiest month (with the highest average wind speed) is March (8.4mph).
The calmest month (with the lowest average wind speed) is August (4.8mph).
Average humidity in September
Saint Clair, PA
- Average humidity in September: 80%
The month with the highest relative humidity is February (83%).
The month with the lowest relative humidity is April (77%).
Average rainfall in September
Saint Clair, PA
- Average rainfall in September: 2.09"
The wettest month (with the highest rainfall) is May (3.39").
The driest month (with the least rainfall) is September (2.09").
Average rainfall days in September
Saint Clair, PA
- Average rainfall days in September: 12.7 days
The month with the highest number of rainy days is May (18.7 days).
The months with the least rainy days are January and November (10.8 days).
Average snowfall in September
Saint Clair, PA
- Average snowfall in September: 0"
The month with the highest snowfall is January (5.47").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Saint Clair, PA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Saint Clair, PA
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 8h and 5min
The month with the most sunshine is July (Average sunshine: 10h and 30min).
The months with the least sunshine are January, February and December (Average sunshine: 4h and 24min).
Average sunshine days in September
Saint Clair, PA
- Average sunshine days in September: 14.9 days
The month with the most sunshine days is November (16.3 days).
The month with the least sunshine days is May (9.6 days).
Average UV index in September
Saint Clair, PA
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in September
Saint Clair, PA
- Average cloud cover in September: 38
The months with the most cloud cover are February and December (Cloud cover 53).
The month with the least cloud cover is July (Cloud cover 32).
Average visibility in September
Saint Clair, PA
- Average visibility in September: 5mi
The month with the highest visibility is April (6mi).
The months with the lowest visibility are January, February, March, May, June, July, August, September, October, November and December (5mi).
Saint Clair, Pennsylvania, USA
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