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
Derby records a mild change in average high-temperature during September, easing from a moderately hot 75.9°F (24.4°C) in August to a pleasant 70.2°F (21.2°C). An average nighttime temperature of 54.7°F (12.6°C) is observed during September.Humidity
The months with the lowest humidity are August and September, with an average relative humidity of 78%.Rainfall
In Derby, in September, during 14.2 rainfall days, 1.57" (40mm) of precipitation is typically accumulated. Throughout the year, there are 160.5 rainfall days, and 24.17" (614mm) of precipitation is accumulated.Snowfall
In Derby, New York, snow does not fall in June through September.Daylight
The average length of the day in September is 12h and 29min.On the first day of the month, sunrise is at 6:41 am and sunset at 7:49 pm. On the last day of September, sunrise is at 7:12 am and sunset at 6:58 pm EDT.
Sunshine
The average sunshine in September is 8.9h.UV index
In Derby, the average daily maximum UV index in September is 3. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV radiation for average individuals.Note: The maximum UV index of 3 during September leads to these instructions:
Undertake protective steps - Recommendations to avoid sunburn are issued. The midday Sun can be dangerous due to its intense radiation; always find shade and reduce exposure. Enhance your sun protection with tightly woven, yet airy clothing.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures?
What are the least humid months?
What is the average humidity in September in Derby?
How many days does it rain in September in Derby?
When it does not snow?
Does it snow in September?
What is the average length of the day in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Derby have in September?
What is the UV index reading in September?
Average temperature in September
Derby, NY
- Average high temperature in September: 70.2°F
The warmest month (with the highest average high temperature) is July (77.2°F).
The month with the lowest average high temperature is January (28.8°F).
- Average low temperature in September: 54.7°F
The month with the highest average low temperature is July (61.3°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).
Average pressure in September
Derby, NY
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Derby, NY
- Average wind speed in September: 7.5mph
The windiest month (with the highest average wind speed) is January (11.8mph).
The calmest month (with the lowest average wind speed) is July (6.9mph).
Average humidity in September
Derby, NY
- Average humidity in September: 78%
The month with the highest relative humidity is February (87%).
The months with the lowest relative humidity are August and September (78%).
Average rainfall in September
Derby, NY
- Average rainfall in September: 1.57"
The wettest month (with the highest rainfall) is July (2.52").
The driest month (with the least rainfall) is January (1.54").
Average rainfall days in September
Derby, NY
- Average rainfall days in September: 14.2 days
The months with the highest number of rainy days are July and October (18.1 days).
The month with the least rainy days is February (7 days).
Average snowfall in September
Derby, NY
- Average snowfall in September: 0"
The month with the highest snowfall is February (5.43").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Derby, NY
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (15.6 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Derby, NY
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in September: 8h and 5min
The month with the most sunshine is August (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 2h and 24min).
Average sunshine days in September
Derby, NY
- Average sunshine days in September: 12.6 days
The month with the most sunshine days is March (13 days).
The month with the least sunshine days is January (8.3 days).
Average UV index in September
Derby, NY
- Average UV index in September: 3
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Derby, NY
- Average cloud cover in September: 34
The month with the most cloud cover is January (Cloud cover 76).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility in September
Derby, NY
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January and February (5mi).
Derby, New York, USA
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