September weather forecastKnoxville, MD
September
Weather in September
The first month of the autumn, September, is also a moderately hot month in Knoxville, Maryland, with temperature in the range of an average low of 57.2°F (14°C) and an average high of 76.8°F (24.9°C).Temperature
Start of September brings a slight shift in the average high-temperature, dipping a bit from August's moderately hot 83.8°F (28.8°C) to a still warm 76.8°F (24.9°C). The low-temperature averages to a refreshing 57.2°F (14°C) during the nights of September.Humidity
The average relative humidity in September is 77%.Rainfall
In September, in Knoxville, the rain falls for 13.8 days. Throughout September, 2.01" (51mm) of precipitation is accumulated. Throughout the year, there are 163.3 rainfall days, and 29.84" (758mm) 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 the month, sunrise is at 6:39 am and sunset at 7:41 pm. On the last day of September, sunrise is at 7:06 am and sunset at 6:54 pm EDT.
Sunshine
In Knoxville, the average sunshine in September is 9h.UV index
In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV radiation for ordinary individuals.Note: In September, the maximum UV index of 4 suggests this advice:
Stay alert. Light-skinned people could suffer burns in less than 30 minutes. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. 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
Average temperature in September
Knoxville, MD
- Average high temperature in September: 76.8°F
The warmest month (with the highest average high temperature) is July (86.4°F).
The month with the lowest average high temperature is January (38.1°F).
- Average low temperature in September: 57.2°F
The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).
Average pressure in September
Knoxville, 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
Knoxville, MD
- Average wind speed in September: 5mph
The windiest month (with the highest average wind speed) is March (7.5mph).
The calmest month (with the lowest average wind speed) is August (4.4mph).
Average humidity in September
Knoxville, MD
- Average humidity in September: 77%
The month with the highest relative humidity is October (79%).
The months with the lowest relative humidity are April and July (74%).
Average rainfall in September
Knoxville, MD
- Average rainfall in September: 2.01"
The wettest month (with the highest rainfall) is May (3.35").
The driest month (with the least rainfall) is January (1.97").
Average rainfall days in September
Knoxville, MD
- Average rainfall days in September: 13.8 days
The month with the highest number of rainy days is May (19.3 days).
The month with the least rainy days is January (9.1 days).
Average snowfall in September
Knoxville, MD
- Average snowfall in September: 0"
The month with the highest snowfall is January (3.62").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Knoxville, MD
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (6.9 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
Knoxville, MD
- Average daylight in September: 12h and 24min
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 42min).
The months with the least sunshine are January and February (Average sunshine: 5h and 0min).
Average sunshine days in September
Knoxville, MD
- Average sunshine days in September: 14.4 days
The month with the most sunshine days is November (18.6 days).
The month with the least sunshine days is May (10.7 days).
Average UV index in September
Knoxville, MD
- Average UV index in September: 4
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
Knoxville, MD
- Average cloud cover in September: 37
The months with the most cloud cover are February and March (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 31).
Average visibility in September
Knoxville, MD
- Average visibility in September: 5mi
The months with the highest visibility are February, March, April, June, July, August and November (6mi).
The months with the lowest visibility are January, May, September, October and December (5mi).
