September weather forecastGrassmere Park, PA
September
Weather in September
The first month of the autumn, September, is still a pleasant month in Grassmere Park, Pennsylvania, with an average temperature fluctuating between 52.2°F (11.2°C) and 72.5°F (22.5°C).Temperature
A subtle change in temperatures is noted as August gives way to September, with average highs reducing from a moderately hot 78.6°F (25.9°C) to a pleasant 72.5°F (22.5°C). Grassmere Park's temperature lowers to a mean of 52.2°F (11.2°C) during the nights in September.Humidity
In September, the average relative humidity is 80%.Rainfall
The month with the least rainfall is September, when the rain falls for 12.8 days and typically collects 2.05" (52mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
In September, the average length of the day is 12h and 28min.On the first day of September, sunrise is at 6:32 am and sunset at 7:37 pm. On the last day of the month, sunrise is at 7:01 am and sunset at 6:48 pm EDT.
Sunshine
In September, the average sunshine is 8.6h.UV index
The average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from unprotected exposure to Sun's UV rays for ordinary individuals.Note: An average maximum UV index of 4 in September leads to these recommendations:
Ensure safety - Imperative it is to shield skin and eyes from damage. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Grassmere Park, PA
- Average high temperature in September: 72.5°F
The warmest month (with the highest average high temperature) is July (81.3°F).
The month with the lowest average high temperature is January (31.8°F).
- Average low temperature in September: 52.2°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 (19°F).
Average pressure in September
Grassmere Park, PA
- Average pressure in September: 30.07"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
Grassmere Park, PA
- Average wind speed in September: 5.5mph
The windiest months (with the highest average wind speed) are March and April (8.1mph).
The calmest month (with the lowest average wind speed) is August (4.8mph).
Average humidity in September
Grassmere Park, 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
Grassmere Park, PA
- Average rainfall in September: 2.05"
The wettest months (with the highest rainfall) are April and May (2.99").
The driest month (with the least rainfall) is September (2.05").
Average rainfall days in September
Grassmere Park, PA
- Average rainfall days in September: 12.8 days
The month with the highest number of rainy days is May (17.8 days).
The month with the least rainy days is January (9.3 days).
Average snowfall in September
Grassmere Park, PA
- Average snowfall in September: 0"
The month with the highest snowfall is January (5.94").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Grassmere Park, PA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (12.9 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Grassmere Park, PA
- Average daylight in September: 12h and 30min
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 36min
The month with the most sunshine is July (Average sunshine: 10h and 12min).
The month with the least sunshine is February (Average sunshine: 3h and 48min).
Average sunshine days in September
Grassmere Park, PA
- Average sunshine days in September: 14.7 days
The month with the most sunshine days is November (16.3 days).
The month with the least sunshine days is February (9.8 days).
Average UV index in September
Grassmere Park, PA
- Average UV index in September: 4
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
Grassmere Park, PA
- Average cloud cover in September: 40
The months with the most cloud cover are February and December (Cloud cover 58).
The month with the least cloud cover is July (Cloud cover 35).
Average visibility in September
Grassmere Park, 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).





