September weather forecastUpper Marlboro, MD
September
Weather in September
The first month of the autumn, September, is still a warm month in Upper Marlboro, Maryland, with an average temperature ranging between min 63°F (17.2°C) and max 78.3°F (25.7°C).Temperature
With the arrival of September, Upper Marlboro experiences a modest decline in average high-temperatures, transitioning from 84.6°F (29.2°C) in August to a still moderately hot 78.3°F (25.7°C). The low-temperature averages to an enjoyable 63°F (17.2°C) during the nights of September.Humidity
The average relative humidity in September is 75%.Rainfall
In Upper Marlboro, in September, it is raining for 13.9 days, with typically 2.36" (60mm) of accumulated precipitation. In Upper Marlboro, during the entire year, the rain falls for 164.8 days and collects up to 32.87" (835mm) of precipitation.Snowfall
In Upper Marlboro, 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 the month, sunrise is at 6:36 am and sunset at 7:36 pm. On the last day of September, sunrise is at 7:02 am and sunset at 6:50 pm EDT.
Sunshine
In September, the average sunshine is 9.1h.UV index
In Upper Marlboro, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for ordinary individuals.Note: During September, 5 as the daily maximum UV index converts into the following advice:
Be vigilant - A duty to shield skin and eyes from injury exists. Protect yourself from the midday Sun's peak UV radiation by minimizing exposure. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Upper Marlboro, MD
- Average high temperature in September: 78.3°F
The warmest month (with the highest average high temperature) is July (86.7°F).
The month with the lowest average high temperature is January (40.1°F).
- Average low temperature in September: 63°F
The month with the highest average low temperature is July (69.8°F).
The coldest month (with the lowest average low temperature) is January (28.2°F).
Average pressure in September
Upper Marlboro, 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
Upper Marlboro, MD
- Average wind speed in September: 6.2mph
The windiest month (with the highest average wind speed) is March (8.5mph).
The calmest months (with the lowest average wind speed) are July and August (5.4mph).
Average humidity in September
Upper Marlboro, MD
- Average humidity in September: 75%
The month with the highest relative humidity is May (77%).
The months with the lowest relative humidity are January, March and April (72%).
Average rainfall in September
Upper Marlboro, MD
- Average rainfall in September: 2.36"
The wettest month (with the highest rainfall) is August (3.94").
The driest month (with the least rainfall) is January (2.05").
Average rainfall days in September
Upper Marlboro, MD
- Average rainfall days in September: 13.9 days
The month with the highest number of rainy days is July (17.8 days).
The month with the least rainy days is November (8.8 days).
Average snowfall in September
Upper Marlboro, MD
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.76").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Upper Marlboro, MD
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (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
Upper Marlboro, MD
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 48min).
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: 11h and 0min).
The month with the least sunshine is February (Average sunshine: 5h and 6min).
Average sunshine days in September
Upper Marlboro, MD
- Average sunshine days in September: 14.7 days
The month with the most sunshine days is November (19.5 days).
The month with the least sunshine days is July (10.8 days).
Average UV index in September
Upper Marlboro, 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
Upper Marlboro, MD
- Average cloud cover in September: 34
The month with the most cloud cover is March (Cloud cover 45).
The month with the least cloud cover is July (Cloud cover 29).
Average visibility in September
Upper Marlboro, 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).
