September weather forecastJefferson, MD
September
Weather in September
The first month of the autumn, September, is still a warm month in Jefferson, Maryland, with an average temperature fluctuating between 61.3°F (16.3°C) and 78.6°F (25.9°C).Temperature
September is characterized by a mild reduction in the average high-temperature, from a warm 85.6°F (29.8°C) in August to a still moderately hot 78.6°F (25.9°C). Nighttime temperatures consistently average a refreshing 61.3°F (16.3°C) during September.Humidity
The average relative humidity in September is 74%.Rainfall
In Jefferson, during September, the rain falls for 12.7 days and regularly aggregates up to 2.09" (53mm) of precipitation. In Jefferson, during the entire year, the rain falls for 161.2 days and collects up to 31.54" (801mm) of precipitation.Snowfall
May through October are months without snowfall.Daylight
In September, the average length of the day is 12h and 26min.On the first day of September, sunrise is at 6:39 am and sunset at 7:40 pm. On the last day of the month, sunrise is at 7:05 am and sunset at 6:53 pm EDT.
Sunshine
The average sunshine in September is 9.1h.UV index
In September, the average daily maximum UV index is 5. A UV Index of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to UV radiation for average individuals.Note: In September, the maximum UV index of 5 suggests this advice:
Heed the precautions - Suggestions to avoid sunburn are made. During midday, the Sun's radiation is strongest, and it's advisable to reduce direct exposure. A hat with a broad brim is indispensable, filtering out up to half of UV rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Jefferson, MD
- Average high temperature in September: 78.6°F
The warmest month (with the highest average high temperature) is July (87.6°F).
The month with the lowest average high temperature is January (40.5°F).
- Average low temperature in September: 61.3°F
The month with the highest average low temperature is July (69.1°F).
The coldest month (with the lowest average low temperature) is January (27.1°F).
Average pressure in September
Jefferson, MD
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).
Average wind speed in September
Jefferson, MD
- Average wind speed in September: 5.4mph
The windiest month (with the highest average wind speed) is March (7.6mph).
The calmest month (with the lowest average wind speed) is August (4.8mph).
Average humidity in September
Jefferson, MD
- Average humidity in September: 74%
The month with the highest relative humidity is October (77%).
The months with the lowest relative humidity are April and July (71%).
Average rainfall in September
Jefferson, MD
- Average rainfall in September: 2.09"
The wettest month (with the highest rainfall) is August (3.78").
The driest month (with the least rainfall) is January (2.05").
Average rainfall days in September
Jefferson, MD
- Average rainfall days in September: 12.7 days
The month with the highest number of rainy days is May (18.2 days).
The month with the least rainy days is November (8.9 days).
Average snowfall in September
Jefferson, MD
- Average snowfall in September: 0"
The month with the highest snowfall is January (3.31").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Jefferson, MD
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (4.9 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
Jefferson, MD
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in September: 9h and 6min
The month with the most sunshine is July (Average sunshine: 10h and 54min).
The months with the least sunshine are January, February and December (Average sunshine: 5h and 12min).
Average sunshine days in September
Jefferson, MD
- Average sunshine days in September: 15.6 days
The month with the most sunshine days is November (19.2 days).
The month with the least sunshine days is July (10.9 days).
Average UV index in September
Jefferson, MD
- 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, November and December (UV index 2).
Average cloud cover in September
Jefferson, MD
- Average cloud cover in September: 36
The month with the most cloud cover is March (Cloud cover 46).
The month with the least cloud cover is July (Cloud cover 30).
Average visibility in September
Jefferson, MD
- 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).





