September weather forecast and climate
Brookline, NH

The first month of the autumn, September, is also an agreeable month in Brookline, New Hampshire, with average temperature varying between 53.8°F (12.1°C) and 72.3°F (22.4°C).

Temperature

In Brookline, the average high-temperature in September slightly decreases, from a moderately hot 80.2°F (26.8°C) in August, to a pleasant 72.3°F (22.4°C). In Brookline, the average low-temperature is 53.8°F (12.1°C).

Humidity

In September, the average relative humidity is 77%.

Rainfall

September is the month with the least rainfall. Rain falls for 11.5 days and accumulates 1.5" (38mm) of precipitation.

Snowfall

In Brookline snow does not fall in June through September.

Daylight

In Brookline, the average length of the day is 12.5h.

Sunshine

In Brookline, the average sunshine is 8.4h.

UV index

In Brookline, New Hampshire, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from the exposure to the Sun's UV rays for the average person.
Note: The average daily UV index of 4 transform into the following instructions:
Take precautions - Protection against sun damage is advised. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.

What is the temperature in September in Brookline?

In Brookline, New Hampshire, in September, the average high-temperature is 72.3°F (22.4°C), and the average low-temperature is 53.8°F (12.1°C).

What is the average humidity in September in Brookline?

In Brookline, the average relative humidity in September is 77%.

How much does it rain in Brookline in September?

In Brookline, in September, during 11.5 rainfall days, 1.5" (38mm) of precipitation is typically accumulated.

What is the driest month in Brookline?

September is the month with the least rainfall. Rain falls for 11.5 days and accumulates 1.5" (38mm) of precipitation.

Does it snow in Brookline in September?

In Brookline, New Hampshire, in September, it doesn't snow. In October, it regularly snows.

When it does not snow in Brookline?

In Brookline snow does not fall in June through September.

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

In September, the average length of the day in Brookline, New Hampshire, is 12.5h.

How many hours of sunshine does Brookline have in September?

The average sunshine in September in Brookline is 8.4h.

What is the UV index reading in September in Brookline?

The average daily maximum UV index in September in Brookline is 4. A UV Index value of 3 to 5 symbolizes a medium hazard to health from unsafe exposure to the Sun's UV rays.
Average temperature in September - Brookline, NH
  • Average high temperature in September: 22.4°C

The warmest month (with the highest average high temperature) is July (27.7°C).
The month with the lowest average high temperature is January (-0.6°C).

  • Average low temperature in September: 12.1°C

The month with the highest average low temperature is July (16.5°C).
The coldest month (with the lowest average low temperature) is January (-7.5°C).

Average pressure in September - Brookline, NH
  • Average pressure in September: 1017.7mbar

The month with the highest atmospheric pressure is November (1018.3mbar).
The month with the lowest atmospheric pressure is June (1013.2mbar).

Average wind speed in September - Brookline, NH
  • Average wind speed in September: 9km/h

The windiest month (with the highest average wind speed) is January (13.3km/h).
The calmest month (with the lowest average wind speed) is August (8.5km/h).

Average humidity in September - Brookline, NH
  • Average humidity in September: 77%

The month with the highest relative humidity is February (81%).
The month with the lowest relative humidity is April (71%).

Average rainfall in September - Brookline, NH
  • Average rainfall in September: 38mm

The wettest months (with the highest rainfall) are October and December (72mm).
The driest month (with the least rainfall) is September (38mm).

Average rainfall days in September - Brookline, NH
  • Average rainfall days in September: 11.5 days

The month with the highest number of rainy days is July (15.8 days).
The month with the least rainy days is February (7.3 days).

Average snowfall in September - Brookline, NH
  • Average snowfall in September: 0mm

The month with the highest snowfall is February (162mm).
Months with the least snowfall are June, July, August and September (0mm).

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

The month with the highest number of snowfall days is January (9.1 days).
Months with the least snowfall days are June, July, August and September (0 days).

Average daylight in September / Average sunshine in September - Brookline, NH
  • Average daylight in September: 12.5h

The month with the longest days is June (Average daylight: 15.3h).
The month with the shortest days is December (Average daylight: 9.1h).

  • Average sunshine in September: 8.4h

The month with the most sunshine is August (Average sunshine: 10.4h).
The month with the least sunshine is February (Average sunshine: 4.6h).

Average sunshine days in September - Brookline, NH
  • Average sunshine days in September: 16.2 days

The month with the most sunshine days is November (17.6 days).
The month with the least sunshine days is May (13.2 days).

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

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

Average cloud cover in September - Brookline, NH
  • Average cloud cover in September: 37

The month with the most cloud cover is March (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 34).

Average visibility in September - Brookline, NH
  • Average visibility in September: 8km

Months with the highest visibility are April, November and December (9km).
Months with the lowest visibility are January, February, March, May, June, July, August, September and October (8km).