September weather forecast
Brockton, MT

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Weather in September

The first month of the autumn, September, is still a pleasant month in Brockton, Montana, with an average temperature fluctuating between 54.3°F (12.4°C) and 71.6°F (22°C).

Temperature

With September's onset, the weather shows a temperature decrease, transitioning from a warm 82.9°F (28.3°C) in August to an agreeable 71.6°F (22°C). Brockton observes an average nighttime low-temperature of 54.3°F (12.4°C) during the month of September.

Humidity

In September, the average relative humidity in Brockton is 46%.

Rainfall

In September, in Brockton, the rain falls for 8 days. Throughout September, 1.5" (38mm) of precipitation is accumulated. Throughout the year, there are 95.7 rainfall days, and 11.69" (297mm) of precipitation is accumulated.

Snowfall

In Brockton, snow does not fall in June through September.

Daylight

The average length of the day in September is 12h and 34min.
On the first day of the month, sunrise is at 6:18 am and sunset at 7:40 pm. On the last day of September, sunrise is at 6:58 am and sunset at 6:40 pm MDT.

Sunshine

In Brockton, the average sunshine in September is 10.1h.

UV index

In Brockton, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV radiation for the average person.
Note: The daily maximum UV index of 4 in September interprets into the following advice:
Undertake protective steps - Recommendations to avoid sunburn are issued. When the Sun's UV radiation is most intense during midday, it's best to find shade and limit exposure. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses. Be informed! The Sun's UV radiation can be nearly doubled due to the reflection from snow.

Frequently asked questions

What are the temperatures in September?

The high-temperature, in September, in Brockton, is 71.6°F (22°C), while the low-temperature averages to 54.3°F (12.4°C). The average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which takes the relative humidity and factors it into the air temperature reading, in August is estimated at 82.4°F (28°C).

What is the average humidity in September in Brockton?

The average relative humidity in September is 46%.

How many days does it rain in September?

In Brockton, in September, it is raining for 8 days, with typically 1.5" (38mm) of accumulated precipitation.

When it does not snow?

June through September are months without snowfall.

Does it snow in September?

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

How many hours of daylight does Brockton have in September?

The average day length in September is 12h and 34min.

When are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 6:18 am and sunset at 7:40 pm. On the last day of the month, sunrise is at 6:58 am and sunset at 6:40 pm MDT.

How many hours of sunshine does Brockton have in September?

In September, the average sunshine duration is 10.1h.

What is the UV index reading in September?

In Brockton, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium health risk from unprotected exposure to UV radiation.
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
Brockton, MT

Average temperature in September - Brockton, MT
  • Average high temperature in September: 71.6°F

The warmest month (with the highest average high temperature) is July (84.4°F).
The month with the lowest average high temperature is February (23°F).

  • Average low temperature in September: 54.3°F

The month with the highest average low temperature is July (63.7°F).
The coldest months (with the lowest average low temperature) are January and February (10.2°F).

Average pressure in September
Brockton, MT

Average pressure in September - Brockton, MT
  • Average pressure in September: 29.93"Hg

The month with the highest atmospheric pressure is February (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.83"Hg).

Average wind speed in September
Brockton, MT

Average wind speed in September - Brockton, MT
  • Average wind speed in September: 10.3mph

The windiest month (with the highest average wind speed) is April (11.2mph).
The calmest month (with the lowest average wind speed) is February (8.8mph).

Average humidity in September
Brockton, MT

Average humidity in September - Brockton, MT
  • Average humidity in September: 46%

The month with the highest relative humidity is January (86%).
The month with the lowest relative humidity is August (42%).

Average rainfall in September
Brockton, MT

Average rainfall in September - Brockton, MT
  • Average rainfall in September: 1.5"

The wettest month (with the highest rainfall) is May (1.89").
The driest month (with the least rainfall) is January (0.51").

Average rainfall days in September
Brockton, MT

Average rainfall days in September - Brockton, MT
  • Average rainfall days in September: 8 days

The month with the highest number of rainy days is May (13.1 days).
The month with the least rainy days is February (3.8 days).

Average snowfall in September
Brockton, MT

Average snowfall in September - Brockton, MT
  • Average snowfall in September: 0"

The month with the highest snowfall is February (3.82").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
Brockton, MT

Average snowfall days in September - Brockton, MT
  • Average snowfall days in September: 0.1 days

The month with the highest number of snowfall days is December (13.6 days).
The months with the least snowfall days are June, July and August (0 days).

Average daylight in September /
Average sunshine in September
Brockton, MT

Average daylight in September / Average sunshine in September - Brockton, MT
  • Average daylight in September: 12h and 4min

The month with the longest days is June (Average daylight: 16h and 0min).
The month with the shortest days is December (Average daylight: 8h and 24min).

  • Average sunshine in September: 10h and 1min

The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is February (Average sunshine: 4h and 24min).

Average sunshine days in September
Brockton, MT

Average sunshine days in September - Brockton, MT
  • Average sunshine days in September: 21.4 days

The month with the most sunshine days is September (21.4 days).
The month with the least sunshine days is April (13.8 days).

Average UV index in September
Brockton, MT

Average UV index in September - Brockton, MT
  • Average UV index in September: 4

The month with the highest UV index is July (UV index 7).
The month with the lowest UV index is December (UV index 1).

Average cloud cover in September
Brockton, MT

Average cloud cover in September - Brockton, MT
  • Average cloud cover in September: 24

The month with the most cloud cover is February (Cloud cover 52).
The month with the least cloud cover is July (Cloud cover 16).

Average visibility in September
Brockton, MT

Average visibility in September - Brockton, MT
  • 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).

Brockton, Montana, USA

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