September weather forecastLancaster, PA

September
Weather in September
September in Lancaster serves as the transition from the scorching summer to the cooler autumn months. The departure from summer is marked by a perceptible drop in the temperature, with highs falling to around 74.8°F (23.8°C). Days start to shorten, hinting at the closing of the summer season. As the season's turn, the trees put on a spectacular show of color, making this a popular time for outdoor photography. Light sweaters and jackets begin making their way out, as evening temperatures cool down.Temperature
September brings a slight decrease in temperature, down from 81°F (27.2°C) in August to a still warm 74.8°F (23.8°C). Lancaster anticipates an average minimum temperature of 56.5°F (13.6°C) in the month of September.Humidity
The average relative humidity in September is 80%.Rainfall
February and September are months with the least rain when the rain falls for 12.2 days and typically aggregates up to 1.89" (48mm) of rain.Snowfall
May through October are months without snowfall.Daylight
In Lancaster, the average length of the day in September is 12h and 26min.On the first day of September, sunrise is at 6:33 am and sunset at 7:36 pm. On the last day of the month, sunrise is at 7:01 am and sunset at 6:48 pm EDT.
Sunshine
In Lancaster, the average sunshine in September is 8.6h.UV index
In Lancaster, 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: The UV index of 4 during September translates into the following guidance:
Proceed with care. Light skin individuals may be exposed to burns in fewer than 30 minutes. To prevent harmful UV exposure, minimize direct contact with the Sun around midday. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Lancaster, PA
- Average high temperature in September: 74.8°F
The warmest month (with the highest average high temperature) is July (82.9°F).
The month with the lowest average high temperature is January (35.4°F).
- Average low temperature in September: 56.5°F
The month with the highest average low temperature is July (64.8°F).
The coldest month (with the lowest average low temperature) is January (23.2°F).
Average pressure in September
Lancaster, 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
Lancaster, PA
- Average wind speed in September: 5.7mph
The windiest month (with the highest average wind speed) is March (9mph).
The calmest month (with the lowest average wind speed) is August (5.1mph).
Average humidity in September
Lancaster, PA
- Average humidity in September: 80%
The month with the highest relative humidity is May (81%).
The month with the lowest relative humidity is April (76%).
Average rainfall in September
Lancaster, PA
- Average rainfall in September: 1.89"
The wettest month (with the highest rainfall) is August (3.35").
The driest months (with the least rainfall) are February and September (1.89").
Average rainfall days in September
Lancaster, PA
- Average rainfall days in September: 12.2 days
The month with the highest number of rainy days is May (17.8 days).
The month with the least rainy days is February (8 days).
Average snowfall in September
Lancaster, PA
- Average snowfall in September: 0"
The month with the highest snowfall is March (3.66").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Lancaster, PA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (6.8 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
Lancaster, PA
- Average daylight in September: 12h and 24min
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 36min
The month with the most sunshine is July (Average sunshine: 10h and 24min).
The month with the least sunshine is February (Average sunshine: 4h and 30min).
Average sunshine days in September
Lancaster, PA
- Average sunshine days in September: 15.9 days
The month with the most sunshine days is November (19.4 days).
The month with the least sunshine days is May (11.3 days).
Average UV index in September
Lancaster, PA
- Average UV index in September: 4
The months with the highest UV index are May, June and July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Lancaster, PA
- Average cloud cover in September: 39
The month with the most cloud cover is February (Cloud cover 50).
The month with the least cloud cover is July (Cloud cover 33).
Average visibility in September
Lancaster, PA
- Average visibility in September: 5mi
The months with the highest visibility are January, February, March, April, June, July, October, November and December (6mi).
The months with the lowest visibility are May, August and September (5mi).





