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
September
Weather in September
Temperature
A subtle shift in Derwood's weather is observed as August turns into September, with the average high temperature reducing from a moderately hot 84.6°F (29.2°C) to a still warm 77.7°F (25.4°C). During September, the temperature tends to dip to an average of 59.9°F (15.5°C) at night.Humidity
The average relative humidity in September in Derwood, Maryland, is 75%.Rainfall
In September, the rain falls for 12.9 days. Throughout September, 1.97" (50mm) of precipitation is accumulated. Throughout the year, in Derwood, there are 154.8 rainfall days, and 29.09" (739mm) of precipitation is accumulated.Snowfall
In Derwood, snow does not fall in June through October.Daylight
The average length of the day in September is 12h and 26min.On the first day of the month, sunrise is at 6:38 am and sunset at 7:38 pm. On the last day of September, sunrise is at 7:04 am and sunset at 6:52 pm EDT.
Sunshine
The average sunshine in September is 9h.UV index
In September, the average daily maximum UV index is 5. A UV Index reading of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV radiation for average individuals.Note: The UV index of 5 during September translates into the following guidance:
Exercise caution. Those with pale skin may experience burns in less than half an hour. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September?
What is the average humidity in September?
How many days does it rain in September?
When it does not snow in Derwood?
What is the average length of the day in September?
What time are sunrise and sunset in September?
How long on average sun shines in September?
What is the UV index reading in September?
Average temperature in September
Derwood, MD
- Average high temperature in September: 77.7°F
The warmest month (with the highest average high temperature) is July (86.9°F).
The month with the lowest average high temperature is January (38.8°F).
- Average low temperature in September: 59.9°F
The month with the highest average low temperature is July (67.6°F).
The coldest month (with the lowest average low temperature) is January (25.2°F).
Average pressure in September
Derwood, 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
Derwood, MD
- Average wind speed in September: 5.5mph
The windiest month (with the highest average wind speed) is March (8mph).
The calmest month (with the lowest average wind speed) is August (4.9mph).
Average humidity in September
Derwood, MD
- Average humidity in September: 75%
The months with the highest relative humidity are May, October and December (77%).
The month with the lowest relative humidity is July (72%).
Average rainfall in September
Derwood, MD
- Average rainfall in September: 1.97"
The wettest month (with the highest rainfall) is August (3.82").
The driest month (with the least rainfall) is January (1.73").
Average rainfall days in September
Derwood, MD
- Average rainfall days in September: 12.9 days
The month with the highest number of rainy days is May (17.4 days).
The month with the least rainy days is January (8.7 days).
Average snowfall in September
Derwood, MD
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.76").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in September
Derwood, MD
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (5.3 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
Derwood, 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: 9h and 0min
The month with the most sunshine is July (Average sunshine: 10h and 48min).
The months with the least sunshine are January, February and December (Average sunshine: 5h and 6min).
Average sunshine days in September
Derwood, MD
- Average sunshine days in September: 14.9 days
The month with the most sunshine days is November (19.6 days).
The month with the least sunshine days is July (11.5 days).
Average UV index in September
Derwood, 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
Derwood, MD
- Average cloud cover in September: 36
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
Derwood, 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).