September weather forecastBethesda, MD
September
Weather in September
The first month of the autumn, September, is also a moderately hot month in Bethesda, Maryland, with temperature in the range of an average low of 61.5°F (16.4°C) and an average high of 78.4°F (25.8°C).Temperature
September heralds a minor drop in average high-temperature, sliding from August's 85.8°F (29.9°C) to a still moderately hot 78.4°F (25.8°C). Nighttime temperature dips to a mean of 61.5°F (16.4°C) during September.Humidity
In Bethesda, the average relative humidity in September is 73%.Rainfall
In Bethesda, in September, it is raining for 12.5 days, with typically 2.05" (52mm) of accumulated precipitation. In Bethesda, Maryland, during the entire year, the rain falls for 150.3 days and collects up to 28.66" (728mm) of precipitation.Snowfall
In Bethesda, snow does not fall in May through October.Daylight
In September, the average length of the day is 12h and 26min.On the first day of September, sunrise is at 6:37 am and sunset at 7:38 pm. On the last day of the month, sunrise is at 7:04 am and sunset at 6:52 pm EDT.
Sunshine
The average sunshine in September is 8.8h.UV index
The average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV rays for ordinary individuals.Note: The maximum UV index of 5 during September leads to these instructions:
Put precautions into practice - Protective measures against sun-induced damage are advised. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. In the presence of strong sunlight, it's crucial to wear sunglasses that ward off UVA and UVB rays.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Bethesda, MD
- Average high temperature in September: 78.4°F
The warmest month (with the highest average high temperature) is July (87.8°F).
The month with the lowest average high temperature is January (39.9°F).
- Average low temperature in September: 61.5°F
The month with the highest average low temperature is July (69.4°F).
The coldest month (with the lowest average low temperature) is January (27°F).
Average pressure in September
Bethesda, 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
Bethesda, MD
- Average wind speed in September: 5.7mph
The windiest month (with the highest average wind speed) is March (8mph).
The calmest month (with the lowest average wind speed) is August (5.1mph).
Average humidity in September
Bethesda, MD
- Average humidity in September: 73%
The month with the highest relative humidity is December (76%).
The month with the lowest relative humidity is July (69%).
Average rainfall in September
Bethesda, MD
- Average rainfall in September: 2.05"
The wettest month (with the highest rainfall) is August (3.82").
The driest month (with the least rainfall) is January (1.69").
Average rainfall days in September
Bethesda, MD
- Average rainfall days in September: 12.5 days
The month with the highest number of rainy days is May (17.1 days).
The month with the least rainy days is November (8.5 days).
Average snowfall in September
Bethesda, MD
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.6").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Bethesda, MD
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (4.4 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
Bethesda, 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: 8h and 48min
The month with the most sunshine is July (Average sunshine: 10h and 42min).
The months with the least sunshine are January, February and December (Average sunshine: 5h and 0min).
Average sunshine days in September
Bethesda, MD
- Average sunshine days in September: 15.8 days
The month with the most sunshine days is November (20.4 days).
The months with the least sunshine days are May and July (12.3 days).
Average UV index in September
Bethesda, 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
Bethesda, MD
- Average cloud cover in September: 37
The month with the most cloud cover is March (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 31).
Average visibility in September
Bethesda, 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).
