September weather forecastPlymouth, NH
September
Weather in September
September ushers in autumn and quieter tourist seasons in Plymouth, with an average high temperature of 68.2°F (20.1°C). Accompanied by a slight increase in rainfall and decrease in average daylight hours, the city slowly retreats from summer's peak. Cooler winds gain strength, heralding the beginning of fall foliage. As September gives way to October, one can expect a noticeable drop in temperatures and the arrival of the spectacular fall season.Temperature
September's arrival in Plymouth coincides with a soft drop in the average high-temperature, subtly decreasing from August's moderately hot 75°F (23.9°C) to a pleasant 68.2°F (20.1°C). Plymouth experiences a consistent average temperature of 48.6°F (9.2°C) throughout the nights in September.Humidity
In Plymouth, New Hampshire, the average relative humidity in September is 80%.Rainfall
In Plymouth, in September, during 9.6 rainfall days, 0.83" (21mm) of precipitation is typically accumulated. In Plymouth, during the entire year, the rain falls for 136.5 days and collects up to 13.54" (344mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
The average length of the day in September in Plymouth is 12h and 29min.On the first day of September in Plymouth, sunrise is at 6:11 am and sunset at 7:21 pm. On the last day of the month, sunrise is at 6:43 am and sunset at 6:29 pm EDT.
Sunshine
In September, the average sunshine is 8.4h.UV index
In September, the average daily maximum UV index in Plymouth is 3. A UV Index reading of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for ordinary individuals.Note: The UV index of 3 in September translates into these instructions:
Be vigilant - Preventing sunburn is recommended. Direct Sun exposure should be minimized especially during midday when radiation is most intense. 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
Plymouth, NH
- Average high temperature in September: 68.2°F
The warmest month (with the highest average high temperature) is July (77°F).
The month with the lowest average high temperature is January (23.9°F).
- Average low temperature in September: 48.6°F
The month with the highest average low temperature is July (56.5°F).
The coldest month (with the lowest average low temperature) is January (11.3°F).
Average pressure in September
Plymouth, 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 (29.91"Hg).
Average wind speed in September
Plymouth, NH
- Average wind speed in September: 4.8mph
The windiest months (with the highest average wind speed) are January, February and April (6.8mph).
The calmest month (with the lowest average wind speed) is August (4.6mph).
Average humidity in September
Plymouth, NH
- Average humidity in September: 80%
The months with the highest relative humidity are January and February (87%).
The month with the lowest relative humidity is May (76%).
Average rainfall in September
Plymouth, NH
- Average rainfall in September: 0.83"
The wettest month (with the highest rainfall) is October (1.5").
The driest month (with the least rainfall) is January (0.79").
Average rainfall days in September
Plymouth, NH
- Average rainfall days in September: 9.6 days
The month with the highest number of rainy days is July (14.2 days).
The month with the least rainy days is November (8.2 days).
Average snowfall in September
Plymouth, NH
- Average snowfall in September: 0"
The month with the highest snowfall is February (4.45").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Plymouth, NH
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (15.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Plymouth, NH
- Average daylight in September: 12h and 30min
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 24min
The month with the most sunshine is August (Average sunshine: 10h and 0min).
The month with the least sunshine is February (Average sunshine: 3h and 54min).
Average sunshine days in September
Plymouth, NH
- Average sunshine days in September: 17 days
The month with the most sunshine days is September (17 days).
The month with the least sunshine days is February (10.8 days).
Average UV index in September
Plymouth, NH
- Average UV index in September: 3
The months with the highest UV index are May, June, July and August (UV index 5).
The month with the lowest UV index is February (UV index 1).
Average cloud cover in September
Plymouth, NH
- Average cloud cover in September: 41
The month with the most cloud cover is February (Cloud cover 59).
The month with the least cloud cover is August (Cloud cover 38).
Average visibility in September
Plymouth, NH
- Average visibility in September: 4mi
The months with the highest visibility are April, May, June, July, August, October, November and December (5mi).
The months with the lowest visibility are January, February, March and September (4mi).
