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
Chartwood's weather subtly changes with the onset of September, barely falling from 83.7°F (28.7°C) in August to a still warm 77.4°F (25.2°C). Chartwood observes an average low-temperature of 63.3°F (17.4°C) during September nights.Humidity
In Chartwood, the average relative humidity in September is 75%.Rainfall
The month with the least rainfall is September, when the rain falls for 11.8 days and typically collects 1.89" (48mm) of precipitation.Snowfall
May through October are months without snowfall.Daylight
In Chartwood, the average length of the day in September is 12h and 26min.On the first day of the month, sunrise is at 6:35 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
The average sunshine in September is 9.2h.UV index
In Chartwood, the average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a medium health hazard from unprotected exposure to Sun's UV rays for average individuals.Note: In September, the maximum UV index of 5 translates into these guidelines:
Guard yourself - Precautionary measures against sun damage are advocated. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. Stay sun-safe with clothing that is both closely woven and worn loosely.
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?
What is the driest month?
How many days does it rain in September?
When it does not snow?
How many hours of daylight does Chartwood have in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Chartwood have in September?
What is the UV index intensity in September?
Average temperature in September
Chartwood, MD
- Average high temperature in September: 77.4°F
The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is January (39.6°F).
- Average low temperature in September: 63.3°F
The month with the highest average low temperature is July (70.7°F).
The coldest month (with the lowest average low temperature) is January (28.4°F).
Average pressure in September
Chartwood, 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
Chartwood, MD
- Average wind speed in September: 7mph
The windiest month (with the highest average wind speed) is March (9.4mph).
The calmest months (with the lowest average wind speed) are July and August (6mph).
Average humidity in September
Chartwood, MD
- Average humidity in September: 75%
The month with the highest relative humidity is May (78%).
The months with the lowest relative humidity are January, March, April and November (72%).
Average rainfall in September
Chartwood, MD
- Average rainfall in September: 1.89"
The wettest month (with the highest rainfall) is August (3.54").
The driest month (with the least rainfall) is September (1.89").
Average rainfall days in September
Chartwood, MD
- Average rainfall days in September: 11.8 days
The month with the highest number of rainy days is May (17.5 days).
The month with the least rainy days is November (9.4 days).
Average snowfall in September
Chartwood, MD
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.05").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Chartwood, MD
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (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
Chartwood, 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 1min
The month with the most sunshine is July (Average sunshine: 10h and 54min).
The month with the least sunshine is February (Average sunshine: 5h and 6min).
Average sunshine days in September
Chartwood, MD
- Average sunshine days in September: 16.4 days
The month with the most sunshine days is November (18.7 days).
The month with the least sunshine days is May (10.8 days).
Average UV index in September
Chartwood, 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
Chartwood, MD
- Average cloud cover in September: 34
The months with the most cloud cover are February and March (Cloud cover 45).
The month with the least cloud cover is July (Cloud cover 28).
Average visibility in September
Chartwood, 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).
Chartwood, Maryland, USA
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