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
September's arrival comes with a mild decrease in the average high-temperature, moving subtly from a moderately hot 83.5°F (28.6°C) in August to a still warm 76.8°F (24.9°C). River Mills experiences an average low-temperature reading of 60.4°F (15.8°C) throughout September.Humidity
The average relative humidity in September is 75%.Rainfall
In September, the rain falls for 13.1 days. Throughout September, 2.17" (55mm) of precipitation is accumulated. Throughout the year, there are 165.5 rainfall days, and 31.65" (804mm) of precipitation is accumulated.Snowfall
May through October are months without snowfall.Daylight
The average length of the day in September is 12h and 26min.On the first day of September, sunrise is at 6:36 am and sunset at 7:37 pm. On the last day of the month, sunrise is at 7:03 am and sunset at 6:50 pm EDT.
Sunshine
In September, the average sunshine is 9.1h.UV index
The average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for average individuals.Note: During September, 5 as the daily maximum UV index converts into the following advice:
Guard yourself - An obligation to protect skin and eyes from harm exists. Midday is when the Sun's radiation is strongest; avoid prolonged exposure during this time. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in September?
What is the average humidity in September?
How many days does it rain in September in River Mills?
When it does not snow?
What is the average length of the day in September?
When are sunrise and sunset in September in River Mills?
How long on average sun shines in September?
What is the UV index intensity in September?
Average temperature in September
River Mills, MD
- Average high temperature in September: 76.8°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 (38.1°F).
- Average low temperature in September: 60.4°F
The month with the highest average low temperature is July (68.7°F).
The coldest month (with the lowest average low temperature) is January (26.2°F).
Average pressure in September
River Mills, 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
River Mills, MD
- Average wind speed in September: 6.2mph
The windiest month (with the highest average wind speed) is March (8.8mph).
The calmest month (with the lowest average wind speed) is August (5.4mph).
Average humidity in September
River Mills, MD
- Average humidity in September: 75%
The months with the highest relative humidity are May and October (77%).
The month with the lowest relative humidity is July (71%).
Average rainfall in September
River Mills, MD
- Average rainfall in September: 2.17"
The wettest month (with the highest rainfall) is August (3.74").
The driest month (with the least rainfall) is January (2.05").
Average rainfall days in September
River Mills, MD
- Average rainfall days in September: 13.1 days
The month with the highest number of rainy days is May (18.2 days).
The month with the least rainy days is January (9.7 days).
Average snowfall in September
River Mills, MD
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.4").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
River Mills, MD
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (4.9 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
River Mills, 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 48min).
The month with the least sunshine is February (Average sunshine: 5h and 0min).
Average sunshine days in September
River Mills, MD
- Average sunshine days in September: 14.5 days
The month with the most sunshine days is November (18.5 days).
The month with the least sunshine days is May (10.4 days).
Average UV index in September
River Mills, 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
River Mills, MD
- Average cloud cover in September: 35
The month with the most cloud cover is March (Cloud cover 46).
The month with the least cloud cover is July (Cloud cover 29).
Average visibility in September
River Mills, 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).
River Mills, Maryland, USA
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