September weather forecastFrederick, MD
September
Weather in September
September marks the beginning of the fall season in Frederick, Maryland, when the leaves start to change color and daylight begins to shorten. The temperatures start to withdraw from the summer swelter, settling at a comfortable average high of 76.3°F (24.6°C). Relaxing into the phase of autumn, September sees a significant drop in average temperature from the past month, promising slightly cooler days. The diminished daylight hours and heightened wind speeds resonate with the changing season. However, despite decreased rainfall, the remaining summer warmth sufficiently maintains the city's vibrance and charm.Temperature
September brings a minor shift in the average high-temperature, adjusting from a moderately hot 83.5°F (28.6°C) in August to a still warm 76.3°F (24.6°C). Throughout September, the temperature falls to an average low of 56.8°F (13.8°C).Humidity
In Frederick, the average relative humidity in September is 78%.Rainfall
In September, the rain falls for 13.4 days. Throughout September, 2.05" (52mm) of precipitation is accumulated. In Frederick, during the entire year, the rain falls for 159.7 days and collects up to 30.04" (763mm) of precipitation.Snowfall
June through October are months without snowfall.Daylight
In Frederick, 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 7:40 pm. On the last day of September, sunrise is at 7:05 am and sunset at 6:53 pm EDT.
Sunshine
In Frederick, Maryland, the average sunshine in September is 8.8h.UV index
In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to UV radiation for ordinary individuals.Note: In September, a daily UV index of 4 turns into the following recommendations:
Act with care - The need to guard against sun damage is communicated. Considering the Sun's intensity during midday, it's wise to minimize direct exposure. Safeguard your eyes, ears, and face from sun rays with the aid of a wide-brim hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Frederick, MD
- Average high temperature in September: 76.3°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 (37.6°F).
- Average low temperature in September: 56.8°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 (23.7°F).
Average pressure in September
Frederick, 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
Frederick, MD
- Average wind speed in September: 5.3mph
The windiest month (with the highest average wind speed) is March (7.8mph).
The calmest months (with the lowest average wind speed) are July and August (4.7mph).
Average humidity in September
Frederick, MD
- Average humidity in September: 78%
The months with the highest relative humidity are May, October and December (79%).
The month with the lowest relative humidity is July (74%).
Average rainfall in September
Frederick, MD
- Average rainfall in September: 2.05"
The wettest month (with the highest rainfall) is May (3.54").
The driest month (with the least rainfall) is January (1.85").
Average rainfall days in September
Frederick, MD
- Average rainfall days in September: 13.4 days
The month with the highest number of rainy days is May (18.6 days).
The month with the least rainy days is January (8.7 days).
Average snowfall in September
Frederick, MD
- Average snowfall in September: 0"
The month with the highest snowfall is January (3.66").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in September
Frederick, MD
- Average snowfall days in September: 0 days
The months with the highest number of snowfall days are January and February (6.3 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
Frederick, 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 24min).
- Average sunshine in September: 8h and 48min
The month with the most sunshine is July (Average sunshine: 10h and 36min).
The months with the least sunshine are January and February (Average sunshine: 4h and 48min).
Average sunshine days in September
Frederick, MD
- Average sunshine days in September: 14.2 days
The month with the most sunshine days is November (18.9 days).
The month with the least sunshine days is May (11.1 days).
Average UV index in September
Frederick, 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
Frederick, MD
- Average cloud cover in September: 38
The months with the most cloud cover are January, February and March (Cloud cover 48).
The month with the least cloud cover is July (Cloud cover 32).
Average visibility in September
Frederick, MD
- Average visibility in September: 5mi
The months with the highest visibility are February, March, April, June, July, August, November and December (6mi).
The months with the lowest visibility are January, May, September and October (5mi).
