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
A mild shift in the average high-temperature occurs in September, reducing from a warm 77.2°F (25.1°C) in August to a pleasant 69.6°F (20.9°C). During September, the nighttime temperature in Alton, New Hampshire, averages of 49.6°F (9.8°C).Humidity
In Alton, New Hampshire, the average relative humidity in September is 80%.Rainfall
The month with the least rainfall is September, when the rain falls for 10.8 days and typically collects 1.61" (41mm) of precipitation.Snowfall
June through September are months without snowfall in Alton.Daylight
The average length of the day in September is 12h and 29min.On the first day of September in Alton, New Hampshire, sunrise is at 6:09 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 Alton, New Hampshire, the average sunshine in September is 8.2h.UV index
The average daily maximum UV index in September is 3. A UV Index of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to UV radiation for the ordinary person.Note: A typical high UV index of 3 in September suggests the following recommendations:
Exercise caution. The susceptibility of light skin individuals to burns is less than 30 minutes. To avoid the Sun's strongest rays, limit exposure around the mid-day period. Limit sun-induced ocular harm with sunglasses that feature UVA and UVB filtration.
Frequently asked questions
What is the average September temperature in Alton?
What is the average humidity in September in Alton?
What is the driest month in Alton?
How much does it rain in Alton in September?
When it does not snow in Alton?
Does it snow in Alton in September?
What is the average length of the day in September in Alton?
What time are sunrise and sunset in September in Alton?
How many hours of sunshine does Alton have in September?
What is the UV index reading in September in Alton?
Average temperature in September
Alton, NH
- Average high temperature in September: 69.6°F
The warmest month (with the highest average high temperature) is July (78.3°F).
The month with the lowest average high temperature is January (26.1°F).
- Average low temperature in September: 49.6°F
The month with the highest average low temperature is July (57.6°F).
The coldest month (with the lowest average low temperature) is January (12.9°F).
Average pressure in September
Alton, NH
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.06"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Alton, NH
- Average wind speed in September: 4.8mph
The windiest months (with the highest average wind speed) are January and February (7.1mph).
The calmest months (with the lowest average wind speed) are July and August (4.7mph).
Average humidity in September
Alton, NH
- Average humidity in September: 80%
The months with the highest relative humidity are January and February (86%).
The month with the lowest relative humidity is April (76%).
Average rainfall in September
Alton, NH
- Average rainfall in September: 1.61"
The wettest month (with the highest rainfall) is October (3.19").
The driest month (with the least rainfall) is September (1.61").
Average rainfall days in September
Alton, NH
- Average rainfall days in September: 10.8 days
The month with the highest number of rainy days is April (15.8 days).
The month with the least rainy days is February (8.3 days).
Average snowfall in September
Alton, NH
- Average snowfall in September: 0"
The month with the highest snowfall is February (9.84").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Alton, NH
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (13.2 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Alton, NH
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 9h and 0min).
- Average sunshine in September: 8h and 1min
The month with the most sunshine is August (Average sunshine: 10h and 12min).
The month with the least sunshine is February (Average sunshine: 4h and 30min).
Average sunshine days in September
Alton, NH
- Average sunshine days in September: 16.9 days
The month with the most sunshine days is September (16.9 days).
The month with the least sunshine days is April (11.4 days).
Average UV index in September
Alton, NH
- Average UV index in September: 3
The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, March, October, November and December (UV index 2).
Average cloud cover in September
Alton, NH
- Average cloud cover in September: 39
The month with the most cloud cover is March (Cloud cover 52).
The month with the least cloud cover is August (Cloud cover 35).
Average visibility in September
Alton, NH
- Average visibility in September: 4mi
The months with the highest visibility are January, March, April, May, June, July, August, October, November and December (5mi).
The months with the lowest visibility are February and September (4mi).
Alton, New Hampshire, USA
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