Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
The onset of September is marked by a minor decrease in temperature, transitioning from 85.3°F (29.6°C) in August to a still moderately hot 78.1°F (25.6°C). Twin Brook observes an average low-temperature of 61°F (16.1°C) during September nights.Humidity
In September, the average relative humidity is 74%.Rainfall
In Twin Brook, Maryland, during September, the rain falls for 14.1 days and regularly aggregates up to 2.4" (61mm) of precipitation. In Twin Brook, during the entire year, the rain falls for 156.8 days and collects up to 30.98" (787mm) of precipitation.Snowfall
In Twin Brook, snow does not fall in May through October.Daylight
The average length of the day in September 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
In Twin Brook, the average sunshine in September is 8.8h.UV index
The average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV rays for the average person.Note: In September, a regular UV index of 5 translates into these guidelines:
Take precautions. Light skin individuals may get burned in less than 30 minutes. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. During bright days, sunglasses that offer UVA and UVB defense are recommended.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures?
What is the average humidity in September in Twin Brook?
How many days does it rain in September?
When it does not snow?
What is the average length of the day in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Twin Brook have in September?
What is the UV index intensity in September?
Average temperature in September
Twin Brook, MD
- Average high temperature in September: 78.1°F
The warmest month (with the highest average high temperature) is July (87.1°F).
The month with the lowest average high temperature is January (39°F).
- Average low temperature in September: 61°F
The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (26.2°F).
Average pressure in September
Twin Brook, 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
Twin Brook, 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 (5mph).
Average humidity in September
Twin Brook, MD
- Average humidity in September: 74%
The month with the highest relative humidity is December (77%).
The month with the lowest relative humidity is July (70%).
Average rainfall in September
Twin Brook, MD
- Average rainfall in September: 2.4"
The wettest month (with the highest rainfall) is August (3.9").
The driest month (with the least rainfall) is January (1.97").
Average rainfall days in September
Twin Brook, MD
- Average rainfall days in September: 14.1 days
The month with the highest number of rainy days is May (17.1 days).
The month with the least rainy days is November (9.2 days).
Average snowfall in September
Twin Brook, MD
- Average snowfall in September: 0"
The month with the highest snowfall is March (3.03").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Twin Brook, MD
- Average snowfall days in September: 0 days
The months with the highest number of snowfall days are January and February (5.3 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
Twin Brook, MD
- Average daylight in September: 12h and 2min
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 5min
The month with the most sunshine is July (Average sunshine: 10h and 48min).
The month with the least sunshine is December (Average sunshine: 5h and 0min).
Average sunshine days in September
Twin Brook, 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 (12 days).
Average UV index in September
Twin Brook, 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
Twin Brook, 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
Twin Brook, 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).
Twin Brook, Maryland, USA
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