September weather forecast
Arimo, ID

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Weather in September

September, the first month of the autumn in Arimo, is also an agreeable month, with an average temperature varying between 49.5°F (9.7°C) and 73°F (22.8°C).

Temperature

Welcoming September, Arimo observes a shift in the average high-temperature, falling from August's moderately hot 83.7°F (28.7°C) to an agreeable 73°F (22.8°C). A sharp divergence from daytime highs is noted during the month of September, with the average nighttime temperature settling at a chilly 49.5°F (9.7°C).

Humidity

The average relative humidity in September is 42%.

Rainfall

In September, the rain falls for 8.6 days. Throughout September, 1.18" (30mm) of precipitation is accumulated. In Arimo, during the entire year, the rain falls for 118.3 days and collects up to 16.42" (417mm) of precipitation.

Snowfall

Months with snowfall are January through May, September through December. September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.35" (9mm) of snow. Throughout the year, there are 68.7 snowfall days, and 48.82" (1240mm) of snow is accumulated.

Daylight

The average length of the day in September is 12h and 28min.
On the first day of the month, sunrise is at 6:54 am and sunset at 8:02 pm. On the last day of September, sunrise is at 7:25 am and sunset at 7:11 pm MDT.

Sunshine

In September, the average sunshine is 9.8h.

UV index

In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to UV radiation for the ordinary person.
Note: The maximum UV index of 4 during September leads to these instructions:
Act with care - The need to guard against sun damage is communicated. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes. Notice this! Nearly double the intensity of the Sun's UV radiation can be caused by snow reflection.
Updated: Jul 19, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the temperature in September?

The high-temperature, in September, in Arimo, is 73°F (22.8°C), while the low-temperature averages to 49.5°F (9.7°C).

What is the average humidity in September?

In September, the average relative humidity in Arimo is 42%.

How many days does it rain in September?

In Arimo, Idaho, in September, it is raining for 8.6 days, with typically 1.18" (30mm) of accumulated precipitation.

When does it start snowing?

September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.35" (9mm) of snow.

How many hours of daylight does Arimo have in September?

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

When are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 6:54 am and sunset at 8:02 pm. On the last day of the month, sunrise is at 7:25 am and sunset at 7:11 pm MDT.

How many hours of sunshine does Arimo have in September?

In Arimo, the average sunshine duration in September is 9.8h.

What is the UV index intensity in September?

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

Average temperature in September
Arimo, ID

Average temperature in September - Arimo, ID
  • Average high temperature in September: 73°F

The warmest month (with the highest average high temperature) is July (84.9°F).
The month with the lowest average high temperature is December (28.9°F).

  • Average low temperature in September: 49.5°F

The month with the highest average low temperature is July (56.3°F).
The coldest month (with the lowest average low temperature) is January (15.3°F).

Average pressure in September
Arimo, ID

Average pressure in September - Arimo, ID
  • Average pressure in September: 29.96"Hg

The month with the highest atmospheric pressure is January (30.3"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).

Average wind speed in September
Arimo, ID

Average wind speed in September - Arimo, ID
  • Average wind speed in September: 6mph

The windiest month (with the highest average wind speed) is April (6.8mph).
The calmest month (with the lowest average wind speed) is January (4.8mph).

Average humidity in September
Arimo, ID

Average humidity in September - Arimo, ID
  • Average humidity in September: 42%

The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is August (35%).

Average rainfall in September
Arimo, ID

Average rainfall in September - Arimo, ID
  • Average rainfall in September: 1.18"

The wettest month (with the highest rainfall) is February (2.05").
The driest month (with the least rainfall) is July (0.55").

Average rainfall days in September
Arimo, ID

Average rainfall days in September - Arimo, ID
  • Average rainfall days in September: 8.6 days

The month with the highest number of rainy days is May (15.9 days).
The month with the least rainy days is January (6.6 days).

Average snowfall in September
Arimo, ID

Average snowfall in September - Arimo, ID
  • Average snowfall in September: 0.35"

The month with the highest snowfall is January (13.78").
The months with the least snowfall are June, July and August (0").

Average snowfall days in September
Arimo, ID

Average snowfall days in September - Arimo, ID
  • Average snowfall days in September: 0.1 days

The month with the highest number of snowfall days is January (15.8 days).
The months with the least snowfall days are June, July and August (0 days).

Average daylight in September /
Average sunshine in September
Arimo, ID

Average daylight in September / Average sunshine in September - Arimo, ID
  • 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: 9h and 5min

The months with the most sunshine are July and August (Average sunshine: 11h and 54min).
The month with the least sunshine is January (Average sunshine: 4h and 42min).

Average sunshine days in September
Arimo, ID

Average sunshine days in September - Arimo, ID
  • Average sunshine days in September: 18.6 days

The month with the most sunshine days is October (19.4 days).
The month with the least sunshine days is February (9.9 days).

Average UV index in September
Arimo, ID

Average UV index in September - Arimo, ID
  • Average UV index in September: 4

The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is January (UV index 1).

Average cloud cover in September
Arimo, ID

Average cloud cover in September - Arimo, ID
  • Average cloud cover in September: 15

The month with the most cloud cover is February (Cloud cover 52).
The months with the least cloud cover are July and August (Cloud cover 11).

Average visibility in September
Arimo, ID

Average visibility in September - Arimo, ID
  • Average visibility in September: 6mi

The months with the highest visibility are April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February and December (4mi).

Arimo, Idaho, USA

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