September weather forecast
Northampton, MA

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Weather in September

September provides a smooth transition from the sweltering summer to pleasant fall with temperatures swinging from 52.7°F (11.5°C) to 72°F (22.2°C). The city of Northampton begins to showcase its fall colors, attracting numerous visitors. September boasts the reduced cloud coverage, making it an ideal month for stargazing. The cooler weather invites exploration of local parks and hiking trails. Moreover, with the UV index lowering to 4, daytime outings become more comfortable.

Temperature

September witnesses a gentle descent in average high-temperature, descending from August's warm 79.3°F (26.3°C) to an agreeable 72°F (22.2°C). In September, Northampton records an average nighttime temperature of 52.7°F (11.5°C).

Humidity

In September, the average relative humidity is 78%.

Rainfall

In Northampton, during September, the rain falls for 10.3 days and regularly aggregates up to 0.98" (25mm) of precipitation. Throughout the year, there are 134.1 rainfall days, and 14.84" (377mm) of precipitation is accumulated.

Snowfall

In Northampton, snow does not fall in June through October.

Daylight

The average length of the day in September is 12h and 28min.
On the first day of the month, sunrise is at 6:16 am and sunset at 7:24 pm. On the last day of September, sunrise is at 6:47 am and sunset at 6:33 pm EDT.

Sunshine

In Northampton, the average sunshine in September is 8.7h.

UV index

The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for the average person.
Note: The maximum UV index, 4 during September, leads to the following recommendations:
Guard yourself - An obligation to protect skin and eyes from harm exists. The Sun's radiation is especially intense around midday; try to stay in shade during this period. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation.

Frequently asked questions

What are the temperatures in September?

September temperatures vary between a high-temperature of 72°F (22.2°C) and a low-temperature of 52.7°F (11.5°C). The average heat index (a.k.a. 'feels like', 'apparent temperature'), which calculates the temperature value influenced by the moisture in the air, in July is evaluated at 87.8°F (31°C).

What is the average humidity in September?

In September, the average relative humidity is 78%.

How many days does it rain in September?

In Northampton, in September, it is raining for 10.3 days, with typically 0.98" (25mm) of accumulated precipitation.

When it does not snow?

In Northampton, snow does not fall in June through October.

How many hours of daylight does Northampton have in September?

In Northampton, the average day length in September is 12h and 28min.

When are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 6:16 am and sunset at 7:24 pm. On the last day of the month, sunrise is at 6:47 am and sunset at 6:33 pm EDT.

How many hours of sunshine does Northampton have in September?

The average sunshine duration in September is 8.7h.

How high is the UV index in September?

In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a moderate health threat from unsafe 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
Northampton, MA

Average temperature in September - Northampton, MA
  • Average high temperature in September: 72°F

The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is January (30.4°F).

  • Average low temperature in September: 52.7°F

The month with the highest average low temperature is July (60.8°F).
The coldest month (with the lowest average low temperature) is January (18°F).

Average pressure in September
Northampton, MA

Average pressure in September - Northampton, MA
  • Average pressure in September: 30.06"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
Northampton, MA

Average wind speed in September - Northampton, MA
  • Average wind speed in September: 5.5mph

The windiest months (with the highest average wind speed) are January, February and March (8mph).
The calmest month (with the lowest average wind speed) is August (5mph).

Average humidity in September
Northampton, MA

Average humidity in September - Northampton, MA
  • Average humidity in September: 78%

The month with the highest relative humidity is February (82%).
The month with the lowest relative humidity is April (72%).

Average rainfall in September
Northampton, MA

Average rainfall in September - Northampton, MA
  • Average rainfall in September: 0.98"

The wettest month (with the highest rainfall) is October (1.61").
The driest month (with the least rainfall) is February (0.91").

Average rainfall days in September
Northampton, MA

Average rainfall days in September - Northampton, MA
  • Average rainfall days in September: 10.3 days

The month with the highest number of rainy days is May (13.9 days).
The month with the least rainy days is January (8.5 days).

Average snowfall in September
Northampton, MA

Average snowfall in September - Northampton, MA
  • Average snowfall in September: 0"

The month with the highest snowfall is February (1.85").
The months with the least snowfall are June, July, August, September and October (0").

Average snowfall days in September
Northampton, MA

Average snowfall days in September - Northampton, MA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (7.7 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in September /
Average sunshine in September
Northampton, MA

Average daylight in September / Average sunshine in September - Northampton, MA
  • Average daylight in September: 12h and 3min

The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 6min).

  • Average sunshine in September: 8h and 4min

The months with the most sunshine are July and August (Average sunshine: 10h and 18min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).

Average sunshine days in September
Northampton, MA

Average sunshine days in September - Northampton, MA
  • Average sunshine days in September: 17.1 days

The month with the most sunshine days is November (19.5 days).
The month with the least sunshine days is June (13.7 days).

Average UV index in September
Northampton, MA

Average UV index in September - Northampton, MA
  • Average UV index in September: 4

The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, February, March, October, November and December (UV index 2).

Average cloud cover in September
Northampton, MA

Average cloud cover in September - Northampton, MA
  • Average cloud cover in September: 37

The months with the most cloud cover are February and March (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 34).

Average visibility in September
Northampton, MA

Average visibility in September - Northampton, MA
  • Average visibility in September: 5mi

The months with the highest visibility are January, March, April, November and December (6mi).
The months with the lowest visibility are February, May, June, July, August, September and October (5mi).

Northampton, Massachusetts, USA

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