Idaho Falls
Idaho, USA
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Idaho Falls, ID

An eye-catching shot of the Snake River, Idaho Falls, with a clear view of the iconic Idaho Falls Temple in the back, through the trees
An eye-catching shot of the Snake River, Idaho Falls, with a clear view of the iconic Idaho Falls Temple in the back, through the trees
The first month of the autumn, September, is still a warm month in Idaho Falls, Idaho, with temperature in the range of an average low of 41.4°F (5.2°C) and an average high of 75°F (23.9°C).

Temperature

In Idaho Falls, the average high-temperature drops, from 85.8°F (29.9°C) in August, to a still moderately hot 75°F (23.9°C). In Idaho Falls, Idaho, in September, the average low-temperature is 41.4°F (5.2°C).

Rainfall

In September, the rain falls for 6 days. Throughout September, 0.9" (23.9mm) of precipitation is accumulated. In Idaho Falls, during the entire year, the rain falls for 100 days and collects up to 14.2" (361.1mm) of precipitation.

Daylight

In Idaho Falls, the average length of the day is 12.5h.

Sunshine

In September, the average sunshine is 10h.

UV index

In Idaho Falls, the average daily maximum UV index in September is 6. A UV Index estimate of 6 to 7 represents a high health vulnerability from unprotected exposure to the Sun's UV rays for ordinary individuals.
Note: The daily maximum UV index of 6 in September interpret into the following advice:
Take precautions and adopt sun safety practices. Protection against sunburn is obliged. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. 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 Idaho Falls?

The average high-temperature, in September, in Idaho Falls, is 75°F (23.9°C), while the average low-temperature is 41.4°F (5.2°C).

How much does it rain in Idaho Falls in September?

In Idaho Falls, Idaho, in September, it is raining for 6 days, with typically 0.9" (23.9mm) of accumulated precipitation.

What is the average length of the day in September in Idaho Falls?

The average length of the day in September in Idaho Falls, Idaho, is 12.5h.

How many hours of sunshine does Idaho Falls have in September?

In September, the average sunshine in Idaho Falls, Idaho, is 10h.

How high is the UV index in September in Idaho Falls?

In September, the average daily maximum UV index in Idaho Falls, Idaho, is 6. A UV Index estimate of 6 to 7 represents a high health risk from the exposure to the Sun's UV rays.
Average temperature in September - Idaho Falls, ID
  • Average high temperature in September: 75.1°F

The warmest month (with the highest average high temperature) is July (86°F).
The month with the lowest average high temperature is January (29.7°F).

  • Average low temperature in September: 41.3°F

The month with the highest average low temperature is July (51.4°F).
The coldest month (with the lowest average low temperature) is January (12.5°F).

Average rainfall in September - Idaho Falls, ID
  • Average rainfall in September: 0.9"

The wettest month (with the highest rainfall) is May (2").
The driest month (with the lowest rainfall) is July (0.7").

Average rainfall days in September - Idaho Falls, ID
  • Average rainfall days in September: 6 days

Months with the highest number of rainy days are January and December (11 days).
Months with the lowest number of rainy days are July and October (5 days).

Average daylight in September / Average sunshine in September - Idaho Falls, ID
  • Average daylight in September: 12.5h

The month with the longest days is June (Average daylight: 15.4h).
The month with shortest days is December (Average daylight: 9h).

  • Average sunshine in September: 10h

The month with most sunshine is July (Average sunshine: 12h).
Months with least sunshine are January, November and December (Average sunshine: 4).

Average UV index in September - Idaho Falls, ID
  • Average UV index in September: 6

The month with the highest UV index is July (UV index 10).
Months with the lowest UV index are January and December (UV index 1).