September weather forecastTwelve Hills, MD
September
Weather in September
September, the first month of the autumn in Twelve Hills, is also a moderately hot month, with an average temperature ranging between min 60.6°F (15.9°C) and max 77°F (25°C).Temperature
The transition into September involves a small decrease in the average high-temperature, dipping slightly from a warm 83.8°F (28.8°C) in August to a still moderately hot 77°F (25°C). Twelve Hills experiences an average temperature drop to a refreshing 60.6°F (15.9°C) during September nights.Humidity
In September, the average relative humidity is 75%.Rainfall
In September, the rain falls for 13.3 days. Throughout September, 2.17" (55mm) of precipitation is accumulated. In Twelve Hills, during the entire year, the rain falls for 159.3 days and collects up to 30.31" (770mm) of precipitation.Snowfall
April through October are months without snowfall.Daylight
In Twelve Hills, the average length of the day in September is 12h and 26min.On the first day of the month, sunrise is at 6:37 am and sunset at 7:38 pm. On the last day of September, sunrise is at 7:03 am and sunset at 6:51 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 medium health hazard from exposure to the Sun's UV rays for the average person.Note: A maximum UV index of 5 in September translates into the following recommendations:
Undertake protective steps - Obligation to safeguard skin and eyes from harm is in place. Being exposed to the midday Sun can have harmful effects due to strong UV radiation; always take precautions. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Twelve Hills, MD
- Average high temperature in September: 77°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 (38.1°F).
- Average low temperature in September: 60.6°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 (26.1°F).
Average pressure in September
Twelve Hills, 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 (29.94"Hg).
Average wind speed in September
Twelve Hills, MD
- Average wind speed in September: 6.1mph
The windiest month (with the highest average wind speed) is March (8.6mph).
The calmest month (with the lowest average wind speed) is August (5.3mph).
Average humidity in September
Twelve Hills, MD
- Average humidity in September: 75%
The months with the highest relative humidity are May and October (77%).
The months with the lowest relative humidity are April and July (72%).
Average rainfall in September
Twelve Hills, MD
- Average rainfall in September: 2.17"
The wettest month (with the highest rainfall) is August (4.06").
The driest month (with the least rainfall) is January (1.85").
Average rainfall days in September
Twelve Hills, MD
- Average rainfall days in September: 13.3 days
The month with the highest number of rainy days is May (18 days).
The month with the least rainy days is January (8.4 days).
Average snowfall in September
Twelve Hills, MD
- Average snowfall in September: 0"
The month with the highest snowfall is March (3.03").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Twelve Hills, MD
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (4.6 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
Twelve Hills, 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 30min).
- Average sunshine in September: 9h and 6min
The month with the most sunshine is July (Average sunshine: 10h and 48min).
The months with the least sunshine are January and February (Average sunshine: 5h and 6min).
Average sunshine days in September
Twelve Hills, MD
- Average sunshine days in September: 14.3 days
The month with the most sunshine days is November (19.6 days).
The month with the least sunshine days is May (11 days).
Average UV index in September
Twelve Hills, 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, February, November and December (UV index 2).
Average cloud cover in September
Twelve Hills, MD
- Average cloud cover in September: 35
The month with the most cloud cover is March (Cloud cover 46).
The month with the least cloud cover is July (Cloud cover 29).
Average visibility in September
Twelve Hills, MD
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).





