September weather forecastLondonderry, VT
September
Weather in September
September, the first month of the autumn in Londonderry, is also an agreeable month, with an average temperature varying between 68.5°F (20.3°C) and 49.3°F (9.6°C).Temperature
The transition into September subtly indicates a reduction in the average high-temperature, down to an agreeable 68.5°F (20.3°C) from August's moderately hot 75.7°F (24.3°C). Londonderry experiences an average low-temperature of 49.3°F (9.6°C) in month of September.Humidity
The average relative humidity in September in Londonderry is 80%.Rainfall
In September, the rain falls for 10.1 days. Throughout September, 0.83" (21mm) of precipitation is accumulated. Throughout the year, there are 133 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 the month, sunrise is at 6:16 am and sunset at 7:25 pm. On the last day of September, in Londonderry, sunrise is at 6:48 am and sunset at 6:33 pm EDT.
Sunshine
In September, the average sunshine in Londonderry is 8.3h.UV index
In September, the average daily maximum UV index is 3. A UV Index reading of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for ordinary individuals.Note: The UV index of 3 during September translates into the following guidance:
Act with care - The need to guard against sun damage is communicated. Exposing oneself to the midday Sun can be harmful due to the strong UV radiation; limit your time outside. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Londonderry, VT
- Average high temperature in September: 68.5°F
The warmest month (with the highest average high temperature) is July (77.5°F).
The month with the lowest average high temperature is January (25.2°F).
- Average low temperature in September: 49.3°F
The month with the highest average low temperature is July (57°F).
The coldest month (with the lowest average low temperature) is January (12.9°F).
Average pressure in September
Londonderry, VT
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.08"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Londonderry, VT
- Average wind speed in September: 5.3mph
The windiest month (with the highest average wind speed) is January (7.9mph).
The calmest month (with the lowest average wind speed) is August (5.2mph).
Average humidity in September
Londonderry, VT
- Average humidity in September: 80%
The month with the highest relative humidity is February (87%).
The months with the lowest relative humidity are April and May (76%).
Average rainfall in September
Londonderry, VT
- Average rainfall in September: 0.83"
The wettest months (with the highest rainfall) are April and October (1.26").
The driest month (with the least rainfall) is March (0.79").
Average rainfall days in September
Londonderry, VT
- Average rainfall days in September: 10.1 days
The month with the highest number of rainy days is May (14.6 days).
The months with the least rainy days are January and February (7.3 days).
Average snowfall in September
Londonderry, VT
- Average snowfall in September: 0"
The month with the highest snowfall is February (4.02").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Londonderry, VT
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (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
Londonderry, VT
- Average daylight in September: 12h and 30min
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 0min).
- Average sunshine in September: 8h and 18min
The months with the most sunshine are July and August (Average sunshine: 10h and 0min).
The month with the least sunshine is February (Average sunshine: 3h and 36min).
Average sunshine days in September
Londonderry, VT
- Average sunshine days in September: 17.1 days
The month with the most sunshine days is November (17.5 days).
The month with the least sunshine days is February (11.7 days).
Average UV index in September
Londonderry, VT
- 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
Londonderry, VT
- Average cloud cover in September: 41
The month with the most cloud cover is February (Cloud cover 61).
The month with the least cloud cover is August (Cloud cover 37).
Average visibility in September
Londonderry, VT
- 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).





