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
The start of September signals a gentle decrease in the average high-temperature, transitioning from 83.7°F (28.7°C) in August to a still moderately hot 76.5°F (24.7°C). During September, Rosemont observes a consistent average nighttime temperature of 59.9°F (15.5°C).Humidity
In Rosemont, the average relative humidity in September is 75%.Rainfall
In Rosemont, in September, during 10.1 rainfall days, 0.63" (16mm) of precipitation is typically accumulated. Throughout the year, there are 111.8 rainfall days, and 9.69" (246mm) of precipitation is accumulated.Snowfall
April through October are months without snowfall.Daylight
The average length of the day in September is 12h and 26min.On the first day of the month, sunrise is at 6:29 am and sunset at 7:32 pm. On the last day of September, sunrise is at 6:57 am and sunset at 6:44 pm EDT.
Sunshine
In Rosemont, the average sunshine in September is 8.6h.UV index
In Rosemont, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for average individuals.Note: The daily maximum UV index of 5 in September interprets into the following advice:
Act with care - Obligation to protect against skin and eye damage is highlighted. To guard against the harmful effects of the Sun, minimize exposure during midday. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September?
What is the average humidity in September?
How many days does it rain in September in Rosemont?
When it does not snow?
What is the average length of the day in September in Rosemont?
What time are sunrise and sunset in September?
How long on average sun shines in September?
What is the UV index reading in September?
Average temperature in September
Rosemont, PA
- Average high temperature in September: 76.5°F
The warmest month (with the highest average high temperature) is July (85.8°F).
The month with the lowest average high temperature is January (36.7°F).
- Average low temperature in September: 59.9°F
The month with the highest average low temperature is July (68.9°F).
The coldest month (with the lowest average low temperature) is January (25°F).
Average pressure in September
Rosemont, 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
Rosemont, PA
- Average wind speed in September: 5.9mph
The windiest month (with the highest average wind speed) is March (8.5mph).
The calmest month (with the lowest average wind speed) is August (5.5mph).
Average humidity in September
Rosemont, PA
- Average humidity in September: 75%
The months with the highest relative humidity are February and October (78%).
The months with the lowest relative humidity are April, July and August (71%).
Average rainfall in September
Rosemont, PA
- Average rainfall in September: 0.63"
The wettest months (with the highest rainfall) are July and August (1.14").
The driest month (with the least rainfall) is January (0.55").
Average rainfall days in September
Rosemont, PA
- Average rainfall days in September: 10.1 days
The month with the highest number of rainy days is July (13.3 days).
The month with the least rainy days is January (5.3 days).
Average snowfall in September
Rosemont, PA
- Average snowfall in September: 0"
The months with the highest snowfall are February and March (0.98").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Rosemont, PA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (4.5 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
Rosemont, PA
- Average daylight in September: 12h and 2min
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 24min).
- Average sunshine in September: 8h and 4min
The month with the most sunshine is July (Average sunshine: 10h and 36min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).
Average sunshine days in September
Rosemont, PA
- Average sunshine days in September: 18.5 days
The month with the most sunshine days is November (22.5 days).
The month with the least sunshine days is July (14.9 days).
Average UV index in September
Rosemont, PA
- Average UV index in September: 5
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Rosemont, PA
- Average cloud cover in September: 39
The month with the most cloud cover is February (Cloud cover 49).
The month with the least cloud cover is July (Cloud cover 32).
Average visibility in September
Rosemont, PA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is May (5mi).
Rosemont, Pennsylvania, USA
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