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
The transition into September involves a small decrease in the average high-temperature, dipping slightly from a moderately hot 80.1°F (26.7°C) in August to an agreeable 72.1°F (22.3°C). During the month of September, the temperature generally drops to a low average of 54°F (12.2°C).Humidity
In September, the average relative humidity is 77%.Rainfall
In Derry, during September, the rain falls for 8.4 days and regularly aggregates up to 0.79" (20mm) of precipitation. Throughout the year, there are 104.4 rainfall days, and 12.95" (329mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall.Daylight
In September, the average length of the day is 12h and 29min.On the first day of September, sunrise is at 6:10 am and sunset at 7:19 pm. On the last day of the month, sunrise is at 6:42 am and sunset at 6:27 pm EDT.
Sunshine
In September, the average sunshine is 8.4h.UV index
In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for the average person.Note: The maximum UV index of 4 during September translates into these guidelines:
Take measures. Individuals with light skin might experience burns in under 30 minutes. Limiting sun exposure during midday hours helps in reducing the harmful effects of UV radiation. To cut down UV radiation exposure by about half, sport a wide-brim hat.
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?
When it does not snow?
Does it snow in September?
What is the average length of the day in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Derry have in September?
How high is the UV index in September?
Average temperature in September
Derry, NH
- Average high temperature in September: 72.1°F
The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is January (30.6°F).
- Average low temperature in September: 54°F
The month with the highest average low temperature is July (61°F).
The coldest month (with the lowest average low temperature) is January (18°F).
Average pressure in September
Derry, NH
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.07"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Derry, NH
- Average wind speed in September: 5.5mph
The windiest month (with the highest average wind speed) is January (8.3mph).
The calmest month (with the lowest average wind speed) is August (5.1mph).
Average humidity in September
Derry, NH
- Average humidity in September: 77%
The month with the highest relative humidity is February (81%).
The month with the lowest relative humidity is April (72%).
Average rainfall in September
Derry, NH
- Average rainfall in September: 0.79"
The wettest month (with the highest rainfall) is October (1.38").
The driest month (with the least rainfall) is January (0.75").
Average rainfall days in September
Derry, NH
- Average rainfall days in September: 8.4 days
The month with the highest number of rainy days is June (12.1 days).
The month with the least rainy days is January (4.1 days).
Average snowfall in September
Derry, NH
- Average snowfall in September: 0"
The month with the highest snowfall is December (2.99").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Derry, NH
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (7.1 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Derry, NH
- 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 2min
The month with the most sunshine is August (Average sunshine: 10h and 24min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).
Average sunshine days in September
Derry, NH
- Average sunshine days in September: 20 days
The months with the most sunshine days are January and December (21.3 days).
The month with the least sunshine days is June (16.7 days).
Average UV index in September
Derry, NH
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in September
Derry, NH
- Average cloud cover in September: 37
The month with the most cloud cover is March (Cloud cover 51).
The month with the least cloud cover is August (Cloud cover 33).
Average visibility in September
Derry, NH
- Average visibility in September: 5mi
The months with the highest visibility are January, April, November and December (6mi).
The months with the lowest visibility are February, March, May, June, July, August, September and October (5mi).
Derry, New Hampshire, USA
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