September weather forecast
Eighteenmile, ID

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Weather in September

The first month of the autumn, September, is still a comfortable month in Eighteenmile, Idaho, with temperature in the range of an average high of 65.8°F (18.8°C) and an average low of 40.1°F (4.5°C).

Temperature

Eighteenmile in September demonstrates a small temperature transition, adjusting from an average high of a warm 75.7°F (24.3°C) in August to a refreshing 65.8°F (18.8°C). From significant daily highs, Eighteenmile's nights in September cool down to an average low-temperature of 40.1°F (4.5°C).

Humidity

In September, the average relative humidity in Eighteenmile is 53%.

Rainfall

In September, in Eighteenmile, the rain falls for 7.9 days. Throughout September, 1.14" (29mm) of precipitation is accumulated. Throughout the year, in Eighteenmile, Idaho, there are 106.1 rainfall days, and 20.83" (529mm) of precipitation is accumulated.

Snowfall

January through July, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 1.2 snowfall days, it receives 1.69" (43mm) of snow. In Eighteenmile, during the entire year, snow falls for 138.1 days and aggregates up to 107.64" (2734mm) of snow.

Daylight

The average length of the day in September in Eighteenmile, Idaho, is 12h and 30min.
On the first day of September in Eighteenmile, sunrise is at 6:51 am and sunset at 8:03 pm. On the last day of the month, sunrise is at 7:25 am and sunset at 7:09 pm MDT.

Sunshine

In September, the average sunshine is 9.9h.

UV index

The average daily maximum UV index in September is 3. A UV Index value of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV rays for ordinary individuals.
Note: The maximum daily UV index of 3 during September translates into the following directions:
Prioritize safety - Recommendations to avert sunburn are shared. Avoid the Sun's strongest UV rays by seeking shade and limiting exposure during midday. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance. Take heed! Reflection from the snow can almost amplify the Sun's UV radiation by double.
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Frequently asked questions

What is the average September temperature in Eighteenmile?

In Eighteenmile, 65.8°F (18.8°C) is the average high-temperature and 40.1°F (4.5°C) is the average low-temperature during September.

What is the average humidity in September in Eighteenmile?

In Eighteenmile, Idaho, the average relative humidity in September is 53%.

How much does it rain in Eighteenmile in September?

In Eighteenmile, in September, it is raining for 7.9 days, with typically 1.14" (29mm) of accumulated precipitation.

When does it start snowing in Eighteenmile?

September is the first month it typically snows. Throughout September, in the average 1.2 snowfall days, it receives 1.69" (43mm) of snow.

How many hours of daylight does Eighteenmile have in September?

In September, the average day length in Eighteenmile is 12h and 30min.

When are sunrise and sunset in September in Eighteenmile?

In September, on the first day of the month, sunrise is at 6:51 am and sunset at 8:03 pm. On the last day of the month, in Eighteenmile, sunrise is at 7:25 am and sunset at 7:09 pm MDT.

How long on average sun shines in September in Eighteenmile?

In September, the average sunshine duration is 9.9h.

What is the UV index intensity in September in Eighteenmile?

In Eighteenmile, Idaho, the average daily maximum UV index in September is 3. A UV Index estimate of 3 to 5 represents a medium health risk from unprotected exposure to 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
Eighteenmile, ID

Average temperature in September - Eighteenmile, ID
  • Average high temperature in September: 65.8°F

The warmest month (with the highest average high temperature) is July (77.4°F).
The month with the lowest average high temperature is December (22.3°F).

  • Average low temperature in September: 40.1°F

The month with the highest average low temperature is August (46.6°F).
The coldest months (with the lowest average low temperature) are January and December (6.8°F).

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Average pressure in September
Eighteenmile, ID

Average pressure in September - Eighteenmile, ID
  • Average pressure in September: 29.99"Hg

The month with the highest atmospheric pressure is January (30.26"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

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Average wind speed in September
Eighteenmile, ID

Average wind speed in September - Eighteenmile, ID
  • Average wind speed in September: 5.5mph

The windiest month (with the highest average wind speed) is June (6.3mph).
The calmest month (with the lowest average wind speed) is January (4.4mph).

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Average humidity in September
Eighteenmile, ID

Average humidity in September - Eighteenmile, ID
  • Average humidity in September: 53%

The months with the highest relative humidity are January and February (94%).
The month with the lowest relative humidity is August (47%).

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Average rainfall in September
Eighteenmile, ID

Average rainfall in September - Eighteenmile, ID
  • Average rainfall in September: 1.14"

The wettest month (with the highest rainfall) is February (2.64").
The driest month (with the least rainfall) is July (0.47").

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Average rainfall days in September
Eighteenmile, ID

Average rainfall days in September - Eighteenmile, ID
  • Average rainfall days in September: 7.9 days

The month with the highest number of rainy days is May (17 days).
The month with the least rainy days is January (3.8 days).

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Average snowfall in September
Eighteenmile, ID

Average snowfall in September - Eighteenmile, ID
  • Average snowfall in September: 1.69"

The month with the highest snowfall is January (19.84").
The month with the least snowfall is August (0").

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Average snowfall days in September
Eighteenmile, ID

Average snowfall days in September - Eighteenmile, ID
  • Average snowfall days in September: 1.2 days

The month with the highest number of snowfall days is December (23 days).
The month with the least snowfall days is August (0 days).

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

Average daylight in September / Average sunshine in September - Eighteenmile, ID
  • Average daylight in September: 12h and 3min

The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).

  • Average sunshine in September: 9h and 5min

The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).

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Average sunshine days in September
Eighteenmile, ID

Average sunshine days in September - Eighteenmile, ID
  • Average sunshine days in September: 19.3 days

The month with the most sunshine days is July (21.2 days).
The month with the least sunshine days is February (5.9 days).

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Average UV index in September
Eighteenmile, ID

Average UV index in September - Eighteenmile, ID
  • Average UV index in September: 3

The months with the highest UV index are June and July (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 1).

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Average cloud cover in September
Eighteenmile, ID

Average cloud cover in September - Eighteenmile, ID
  • Average cloud cover in September: 19

The month with the most cloud cover is February (Cloud cover 67).
The month with the least cloud cover is July (Cloud cover 13).

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Average visibility in September
Eighteenmile, ID

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

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

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Eighteenmile, Idaho, USA

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