September weather forecast
Durham, NH

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Weather in September

September ushers in the early signs of fall in Durham. Compared to August, the temperatures in September show a decline but remain comfortably warm. The month of September marks a substantial decrease in rainfall, measuring at 1.46" (37mm). As fall approaches, the days shorten and temperatures drop, preparing Durham for the oncoming cooler months. Regardless, lingering warmth from the summer offers an opportunity to enjoy the stunning fall foliage.

Temperature

In the transition to September, Durham observes a minor drop in the average high-temperature, shifting from a moderately hot 76.8°F (24.9°C) in August to a pleasant 69.6°F (20.9°C). In the month of September, Durham experiences an average low-temperature of 55°F (12.8°C).

Humidity

The average relative humidity in September is 79%.

Rainfall

September is the month with the least rainfall. Rain falls for 11.4 days and accumulates 1.46" (37mm) of precipitation.

Snowfall

In Durham, New Hampshire, snow does not fall in May through September.

Daylight

In September, the average length of the day is 12h and 29min.
On the first day of the month, sunrise is at 6:08 am and sunset at 7:18 pm. On the last day of September, sunrise is at 6:40 am and sunset at 6:26 pm EDT.

Sunshine

The average sunshine in September in Durham is 8.5h.

UV index

In Durham, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for the ordinary person.
Note: An average maximum UV index of 4 in September leads to these recommendations:
Take precautions - Protection against sun damage is advised. To protect against the Sun's most potent rays, avoid direct exposure around midday. During bright days, sunglasses that offer UVA and UVB defense are recommended.
Updated: Feb 13, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the temperatures in Durham in September?

During September, Durham experiences an average high-temperature of 69.6°F (20.9°C) and a low-temperature of 55°F (12.8°C).

What is the average humidity in September in Durham?

The average relative humidity in September in Durham, New Hampshire, is 79%.

What is the driest month in Durham?

The month with the least rainfall is September, when the rain falls for 11.4 days and typically collects 1.46" (37mm) of precipitation.

How much does it rain in Durham in September?

In September, the rain falls for 11.4 days. Throughout September, 1.46" (37mm) of precipitation is accumulated.

When it does not snow in Durham?

May through September are months without snowfall.

Does it snow in Durham in September?

In Durham, in September, it doesn't snow. In October, it regularly snows.

What is the average length of the day in September in Durham?

In Durham, the average day length in September is 12h and 29min.

What time are sunrise and sunset in September in Durham?

In September, on the first day of the month, sunrise is at 6:08 am and sunset at 7:18 pm. On the last day of the month, sunrise is at 6:40 am and sunset at 6:26 pm EDT.

How long on average sun shines in September in Durham?

The average sunshine duration in September in Durham, New Hampshire, is 8.5h.

What is the UV index reading in September in Durham?

In Durham, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a moderate health threat from exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Durham, NH

Average temperature in September - Durham, NH
  • Average high temperature in September: 69.6°F

The warmest month (with the highest average high temperature) is July (77.4°F).
The month with the lowest average high temperature is January (31.5°F).

  • Average low temperature in September: 55°F

The month with the highest average low temperature is July (61.5°F).
The coldest month (with the lowest average low temperature) is January (19.8°F).

Average pressure in September
Durham, NH

Average pressure in September - Durham, 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 (29.92"Hg).

Average wind speed in September
Durham, NH

Average wind speed in September - Durham, NH
  • Average wind speed in September: 7mph

The windiest month (with the highest average wind speed) is January (10.8mph).
The calmest months (with the lowest average wind speed) are July and August (6.2mph).

Average humidity in September
Durham, NH

Average humidity in September - Durham, NH
  • Average humidity in September: 79%

The months with the highest relative humidity are January and February (80%).
The months with the lowest relative humidity are April and November (75%).

Average rainfall in September
Durham, NH

Average rainfall in September - Durham, NH
  • Average rainfall in September: 1.46"

The wettest months (with the highest rainfall) are October and December (2.87").
The driest month (with the least rainfall) is September (1.46").

Average rainfall days in September
Durham, NH

Average rainfall days in September - Durham, NH
  • Average rainfall days in September: 11.4 days

The month with the highest number of rainy days is May (15 days).
The month with the least rainy days is February (7.6 days).

Average snowfall in September
Durham, NH

Average snowfall in September - Durham, NH
  • Average snowfall in September: 0"

The month with the highest snowfall is December (4.53").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in September
Durham, NH

Average snowfall days in September - Durham, NH
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (8.7 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

Average daylight in September /
Average sunshine in September
Durham, NH

Average daylight in September / Average sunshine in September - Durham, 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 3min

The month with the most sunshine is August (Average sunshine: 10h and 36min).
The months with the least sunshine are February and December (Average sunshine: 4h and 48min).

Average sunshine days in September
Durham, NH

Average sunshine days in September - Durham, NH
  • Average sunshine days in September: 16.5 days

The month with the most sunshine days is November (17.1 days).
The month with the least sunshine days is April (13.2 days).

Average UV index in September
Durham, NH

Average UV index in September - Durham, NH
  • Average UV index in September: 4

The months with the highest UV index are 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
Durham, NH

Average cloud cover in September - Durham, NH
  • Average cloud cover in September: 33

The month with the most cloud cover is March (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 30).

Average visibility in September
Durham, NH

Average visibility in September - Durham, NH
  • Average visibility in September: 6mi

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

Durham, New Hampshire, USA

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