September weather forecast
International Falls, MN

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The Rainy River draining into the Rainy Lake, dense road network, and a townscape of International Falls City in Minnesota
The Rainy River draining into the Rainy Lake, dense road network, and a townscape of International Falls City in Minnesota

Weather in September

September ushers in the much-awaited fall season in International Falls. The city experiences a notable transition in its weather, being cooler than August and becoming even cooler in October. The lush landscapes of Minnesota begin to display a riot of fall colors, inviting nature-lovers to take a stroll. Rainfall enters a decline, heading towards the drier winter days. Despite the decrease in daylight hours, the residents enjoy comfortable weather and moderate sunshine.

Temperature

International Falls's progression into September involves a drop in the average high-temperature, receding from a moderately hot 76.1°F (24.5°C) in August to a comfortable 65.8°F (18.8°C). September sees the temperature falling to a mean low of 47.3°F (8.5°C).

Humidity

In International Falls, the average relative humidity in September is 75%.

Rainfall

In International Falls, during September, the rain falls for 11.6 days and regularly aggregates up to 1.81" (46mm) of precipitation. Throughout the year, there are 110.5 rainfall days, and 19.29" (490mm) of precipitation is accumulated.

Snowfall

In International Falls, 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 6:31 am and sunset at 7:54 pm. On the last day of September, in International Falls, sunrise is at 7:12 am and sunset at 6:53 pm CDT.

Sunshine

In September, the average sunshine is 8h.

UV index

The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for the ordinary person.
Note: The UV index of 4 during September leads to these advisories:
Adopt protective measures - Suggestions to resist sunburn are offered. Direct Sun exposure should be minimized especially during midday when radiation is most intense. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays. Pay attention! The reflection of snow can enhance the Sun's UV radiation almost double.

Frequently asked questions

What are September temperatures?

In International Falls, 65.8°F (18.8°C) is the average high-temperature and 47.3°F (8.5°C) is the average low-temperature during September.

What is the average humidity in September?

The average relative humidity in September is 75%.

How much does it rain in September?

In September, the rain falls for 11.6 days. Throughout September, 1.81" (46mm) of precipitation is accumulated.

When it does not snow?

In International Falls, snow does not fall in June through September.

Does it snow in September?

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

What is the average length of the day in September?

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

When are sunrise and sunset in September?

On the first day of September, sunrise is at 6:31 am and sunset at 7:54 pm. On the last day of the month, sunrise is at 7:12 am and sunset at 6:53 pm CDT.

How long on average sun shines in September?

The average sunshine duration in September is 8h.

What is the UV index reading in September?

In International Falls, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium hazard to health from exposure to the Sun's 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
International Falls, MN

Average temperature in September - International Falls, MN
  • Average high temperature in September: 65.8°F

The warmest month (with the highest average high temperature) is July (78.6°F).
The month with the lowest average high temperature is January (13.8°F).

  • Average low temperature in September: 47.3°F

The month with the highest average low temperature is July (56.8°F).
The coldest month (with the lowest average low temperature) is January (-0.6°F).

Average pressure in September
International Falls, MN

Average pressure in September - International Falls, MN
  • Average pressure in September: 29.97"Hg

The month with the highest atmospheric pressure is February (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).

Average wind speed in September
International Falls, MN

Average wind speed in September - International Falls, MN
  • Average wind speed in September: 6.9mph

The windiest month (with the highest average wind speed) is October (7.3mph).
The calmest month (with the lowest average wind speed) is August (6.2mph).

Average humidity in September
International Falls, MN

Average humidity in September - International Falls, MN
  • Average humidity in September: 75%

The months with the highest relative humidity are January and February (94%).
The month with the lowest relative humidity is May (67%).

Average rainfall in September
International Falls, MN

Average rainfall in September - International Falls, MN
  • Average rainfall in September: 1.81"

The wettest month (with the highest rainfall) is June (2.32").
The driest month (with the least rainfall) is February (0.91").

Average rainfall days in September
International Falls, MN

Average rainfall days in September - International Falls, MN
  • Average rainfall days in September: 11.6 days

The month with the highest number of rainy days is June (15.7 days).
The month with the least rainy days is February (1.3 days).

Average snowfall in September
International Falls, MN

Average snowfall in September - International Falls, MN
  • Average snowfall in September: 0"

The month with the highest snowfall is December (7.95").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
International Falls, MN

Average snowfall days in September - International Falls, MN
  • Average snowfall days in September: 0.2 days

The month with the highest number of snowfall days is January (23.8 days).
The months with the least snowfall days are June, July and August (0 days).

Average daylight in September /
Average sunshine in September
International Falls, MN

Average daylight in September / Average sunshine in September - International Falls, MN
  • Average daylight in September: 12h and 4min

The month with the longest days is June (Average daylight: 16h and 6min).
The month with the shortest days is December (Average daylight: 8h and 24min).

  • Average sunshine in September: 8h and 0min

The month with the most sunshine is July (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 1h and 30min).

Average sunshine days in September
International Falls, MN

Average sunshine days in September - International Falls, MN
  • Average sunshine days in September: 15.9 days

The month with the most sunshine days is September (15.9 days).
The month with the least sunshine days is January (8.3 days).

Average UV index in September
International Falls, MN

Average UV index in September - International Falls, MN
  • Average UV index in September: 4

The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, March, October, November and December (UV index 1).

Average cloud cover in September
International Falls, MN

Average cloud cover in September - International Falls, MN
  • Average cloud cover in September: 43

The month with the most cloud cover is January (Cloud cover 85).
The month with the least cloud cover is July (Cloud cover 34).

Average visibility in September
International Falls, MN

Average visibility in September - International Falls, MN
  • Average visibility in September: 5mi

The months with the highest visibility are May, June, July and August (6mi).
The months with the lowest visibility are January and February (3mi).

International Falls, Minnesota, USA

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