September weather forecastOld Germantown, MD
September
Weather in September
September, the first month of the autumn in Old Germantown, is still a warm month, with an average temperature varying between 59.2°F (15.1°C) and 77.5°F (25.3°C).Temperature
The shift from August to September includes a small decrease in the average high-temperature, from a moderately hot 84.6°F (29.2°C) to a still warm 77.5°F (25.3°C). During September, Old Germantown records an average temperature of 59.2°F (15.1°C) at night.Humidity
In Old Germantown, the average relative humidity in September is 76%.Rainfall
In Old Germantown, in September, during 14.2 rainfall days, 2.17" (55mm) of precipitation is typically accumulated. In Old Germantown, during the entire year, the rain falls for 159.4 days and collects up to 30.71" (780mm) of precipitation.Snowfall
June through October are months without snowfall.Daylight
In September, the average length of the day is 12h and 26min.On the first day of the month, sunrise is at 6:38 am and sunset at 7:39 pm. On the last day of September, sunrise is at 7:04 am and sunset at 6:52 pm EDT.
Sunshine
In September, the average sunshine is 9h.UV index
In Old Germantown, the average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV radiation for the ordinary person.Note: In September, a regular UV index of 5 translates into these guidelines:
Be vigilant - Preventing sunburn is recommended. Midday is when the Sun's radiation is strongest; avoid prolonged exposure during this time. Wearing a wide-brim hat can block approximately 50% of UV radiation, protecting the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Old Germantown, MD
- Average high temperature in September: 77.5°F
The warmest month (with the highest average high temperature) is July (86.5°F).
The month with the lowest average high temperature is January (38.8°F).
- Average low temperature in September: 59.2°F
The month with the highest average low temperature is July (66.9°F).
The coldest month (with the lowest average low temperature) is January (25.2°F).
Average pressure in September
Old Germantown, MD
- Average pressure in September: 30.06"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
Old Germantown, MD
- Average wind speed in September: 5.4mph
The windiest month (with the highest average wind speed) is March (7.8mph).
The calmest months (with the lowest average wind speed) are July and August (4.8mph).
Average humidity in September
Old Germantown, MD
- Average humidity in September: 76%
The months with the highest relative humidity are October and December (78%).
The month with the lowest relative humidity is July (72%).
Average rainfall in September
Old Germantown, MD
- Average rainfall in September: 2.17"
The wettest month (with the highest rainfall) is August (3.78").
The driest months (with the least rainfall) are January and February (1.97").
Average rainfall days in September
Old Germantown, MD
- Average rainfall days in September: 14.2 days
The month with the highest number of rainy days is May (17.5 days).
The months with the least rainy days are January and November (9.5 days).
Average snowfall in September
Old Germantown, MD
- Average snowfall in September: 0"
The month with the highest snowfall is March (2.83").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in September
Old Germantown, MD
- Average snowfall days in September: 0 days
The months with the highest number of snowfall days are January and February (5.8 days).
The months with the least snowfall days are June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Old Germantown, 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 0min
The month with the most sunshine is July (Average sunshine: 10h and 54min).
The month with the least sunshine is January (Average sunshine: 5h and 0min).
Average sunshine days in September
Old Germantown, MD
- Average sunshine days in September: 14.1 days
The month with the most sunshine days is November (19 days).
The month with the least sunshine days is July (11.3 days).
Average UV index in September
Old Germantown, 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
Old Germantown, MD
- Average cloud cover in September: 37
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
Old Germantown, 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).
