September weather forecastGrantham, NH
September
Weather in September
September, the first month of the autumn in Grantham, is also an agreeable month, with an average temperature varying between 68.9°F (20.5°C) and 49.3°F (9.6°C).Temperature
The transition into September subtly indicates a reduction in the average high-temperature, down to a pleasant 68.9°F (20.5°C) from August's moderately hot 76.6°F (24.8°C). During the month of September, Grantham anticipates a mean low-temperature of 49.3°F (9.6°C).Humidity
The average relative humidity in September is 80%.Rainfall
The month with the least rainfall is September, when the rain falls for 11.5 days and typically collects 2.05" (52mm) of precipitation.Snowfall
In Grantham, snow does not fall in June through September.Daylight
In Grantham, the average length of the day in September is 12h and 29min.On the first day of September, sunrise is at 6:13 am and sunset at 7:23 pm. On the last day of the month, sunrise is at 6:45 am and sunset at 6:30 pm EDT.
Sunshine
In Grantham, 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 medium health hazard from exposure to the Sun's UV rays for average individuals.Note: In September, a regular UV index of 3 translates into these guidelines:
Adopt protective measures - Suggestions to resist sunburn are offered. For health reasons, it's advisable to reduce direct sun exposure during peak hours around midday. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Grantham, NH
- Average high temperature in September: 68.9°F
The warmest month (with the highest average high temperature) is July (78.8°F).
The month with the lowest average high temperature is January (25.9°F).
- Average low temperature in September: 49.3°F
The month with the highest average low temperature is July (57.2°F).
The coldest month (with the lowest average low temperature) is January (13.3°F).
Average pressure in September
Grantham, 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
Grantham, NH
- Average wind speed in September: 5.2mph
The windiest months (with the highest average wind speed) are January, February, March and April (7.6mph).
The calmest month (with the lowest average wind speed) is August (5mph).
Average humidity in September
Grantham, 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 (75%).
Average rainfall in September
Grantham, NH
- Average rainfall in September: 2.05"
The wettest month (with the highest rainfall) is October (3.39").
The driest month (with the least rainfall) is September (2.05").
Average rainfall days in September
Grantham, NH
- Average rainfall days in September: 11.5 days
The month with the highest number of rainy days is June (16.8 days).
The month with the least rainy days is February (7.9 days).
Average snowfall in September
Grantham, NH
- Average snowfall in September: 0"
The month with the highest snowfall is February (11.18").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Grantham, NH
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (14.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Grantham, 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 12min
The month with the most sunshine is August (Average sunshine: 10h and 6min).
The month with the least sunshine is February (Average sunshine: 4h and 0min).
Average sunshine days in September
Grantham, NH
- Average sunshine days in September: 16.8 days
The month with the most sunshine days is September (16.8 days).
The month with the least sunshine days is February (11.3 days).
Average UV index in September
Grantham, NH
- Average UV index in September: 3
The months with the highest UV index are May, June, July and August (UV index 5).
The months with the lowest UV index are February and December (UV index 1).
Average cloud cover in September
Grantham, NH
- Average cloud cover in September: 40
The month with the most cloud cover is February (Cloud cover 58).
The month with the least cloud cover is August (Cloud cover 36).
Average visibility in September
Grantham, NH
- Average visibility in September: 5mi
The months with the highest visibility are January, March, April, May, June, July, August, September, October, November and December (5mi).
The month with the lowest visibility is February (4mi).
