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
With the onset of September, Mercer's climate undergoes a slight change as the average high-temperature moves from a moderately hot 79.2°F (26.2°C) in August to an agreeable 72.9°F (22.7°C). An average nighttime temperature of 53.4°F (11.9°C) is noted in Mercer during the month of September.Humidity
In Mercer, Pennsylvania, the average relative humidity in September is 81%.Rainfall
In September, the rain falls for 13.8 days. Throughout September, 2.24" (57mm) of precipitation is accumulated. In Mercer, Pennsylvania, during the entire year, the rain falls for 180.8 days and collects up to 36.65" (931mm) of precipitation.Snowfall
In Mercer, snow does not fall in June through September.Daylight
In September, the average length of the day in Mercer is 12h and 28min.On the first day of September, sunrise is at 6:48 am and sunset at 7:53 pm. On the last day of the month, sunrise is at 7:17 am and sunset at 7:04 pm EDT.
Sunshine
In Mercer, the average sunshine in September is 8.2h.UV index
In September, the average daily maximum UV index in Mercer, Pennsylvania, is 3. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for the average person.Note: The maximum UV index of 3 during September translates into these guidelines:
Take heed. Individuals of lighter complexion can be burned in less than half an hour. During midday, the Sun's radiation is strongest, and it's advisable to reduce direct exposure. Employ a wide-brim hat for potent defense against up to 50% of UV rays.
Frequently asked questions
What is the average September temperature in Mercer?
What is the average humidity in September in Mercer?
How many days does it rain in September in Mercer?
When it does not snow in Mercer?
Does it snow in Mercer in September?
What is the average length of the day in September in Mercer?
When are sunrise and sunset in September in Mercer?
How long on average sun shines in September in Mercer?
What is the UV index reading in September in Mercer?
Average temperature in September
Mercer, PA
- Average high temperature in September: 72.9°F
The warmest month (with the highest average high temperature) is July (80.4°F).
The month with the lowest average high temperature is January (30.6°F).
- Average low temperature in September: 53.4°F
The month with the highest average low temperature is July (59.5°F).
The coldest month (with the lowest average low temperature) is January (18.3°F).
Average pressure in September
Mercer, PA
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in September
Mercer, PA
- Average wind speed in September: 5.6mph
The windiest month (with the highest average wind speed) is January (8.3mph).
The calmest months (with the lowest average wind speed) are July and August (5.2mph).
Average humidity in September
Mercer, PA
- Average humidity in September: 81%
The month with the highest relative humidity is February (89%).
The months with the lowest relative humidity are April, May and July (79%).
Average rainfall in September
Mercer, PA
- Average rainfall in September: 2.24"
The wettest months (with the highest rainfall) are April and June (3.74").
The driest month (with the least rainfall) is November (2.2").
Average rainfall days in September
Mercer, PA
- Average rainfall days in September: 13.8 days
The month with the highest number of rainy days is May (20.9 days).
The month with the least rainy days is January (8.3 days).
Average snowfall in September
Mercer, PA
- Average snowfall in September: 0"
The month with the highest snowfall is January (8.27").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Mercer, PA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (19.6 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Mercer, PA
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 8h and 1min
The months with the most sunshine are July and August (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 2h and 24min).
Average sunshine days in September
Mercer, PA
- Average sunshine days in September: 14 days
The month with the most sunshine days is September (14 days).
The month with the least sunshine days is February (6.2 days).
Average UV index in September
Mercer, PA
- Average UV index in September: 3
The months with the highest UV index are May, June, July and August (UV index 5).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Mercer, PA
- Average cloud cover in September: 41
The month with the most cloud cover is January (Cloud cover 75).
The month with the least cloud cover is August (Cloud cover 36).
Average visibility in September
Mercer, PA
- Average visibility in September: 5mi
The months with the highest visibility are March, April, May, June, July, August, September, October and November (5mi).
The months with the lowest visibility are January, February and December (4mi).
Mercer, Pennsylvania, USA
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