September weather forecast
Rexburg, ID

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The crossroads near a large lit temple in Rexburg, Idaho, with a view of the rest of the city and a colorful, cloudy sunset sky on the horizon
The crossroads near a large lit temple in Rexburg, Idaho, with a view of the rest of the city and a colorful, cloudy sunset sky on the horizon

Weather in September

September brings along the onset of fall and with it an alteration in Rexburg's weather conditions. Temperatures experience a marked decrease, with highs averaging around 72.7°F (22.6°C), signaling the transition from summer to autumn. Sunshine remains abundant but no longer bears the intensity of the summer sun. September marks the beginning of autumn's lovely hues, accomplished with crisp mornings and cooler nights. Moving into October, the change in seasons becomes even more evident.

Temperature

The start of September signals a decrease in the average high-temperature, transitioning from a moderately hot 82.9°F (28.3°C) in August to a pleasant 72.7°F (22.6°C). September presents a pronounced difference from daytime highs, with a consistent average low-temperature of 47.3°F (8.5°C).

Humidity

The average relative humidity in September is 43%.

Rainfall

In Rexburg, Idaho, in September, during 9 rainfall days, 0.91" (23mm) of precipitation is typically accumulated. Throughout the year, there are 120.3 rainfall days, and 11.02" (280mm) of precipitation is accumulated.

Snowfall

January through May, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.04" (1mm) of snow. Throughout the year, there are 84.8 snowfall days, and 31.85" (809mm) of snow is accumulated.

Daylight

In September, the average length of the day is 12h and 29min.
On the first day of September, sunrise is at 6:51 am and sunset at 8:02 pm. On the last day of the month, sunrise is at 7:24 am and sunset at 7:09 pm MDT.

Sunshine

In September, the average sunshine is 10h.

UV index

In September, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for the ordinary person.
Note: The maximum UV index of 4 during September translates into these guidelines:
Be vigilant - Preventing sunburn is recommended. Being exposed to the midday Sun can have harmful effects due to strong UV radiation; always take precautions. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly. Take heed! The reflection of snow can intensify the Sun's UV radiation nearly double.

Frequently asked questions

What are the temperatures in September?

In September, the average high-temperature and low-temperature are 72.7°F (22.6°C) and 47.3°F (8.5°C) respectively. In July, the average heat index (a.k.a. 'feels like', 'felt air temperature'), which calculates the temperature value influenced by the moisture in the air, is appraised at 84.2°F (29°C).

What is the average humidity in September?

In September, the average relative humidity is 43%.

How many days does it rain in September?

In September, in Rexburg, the rain falls for 9 days. Throughout September, 0.91" (23mm) of precipitation is accumulated.

When does it start to snow?

September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.04" (1mm) of snow.

What is the average length of the day in September?

In September, the average day length in Rexburg is 12h and 29min.

What time are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 6:51 am and sunset at 8:02 pm. On the last day of the month, sunrise is at 7:24 am and sunset at 7:09 pm MDT.

How many hours of sunshine does Rexburg have in September?

In Rexburg, the average sunshine duration in September is 10h.

What is the UV index intensity in September?

In Rexburg, the average daily maximum UV index in September 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
Rexburg, ID

Average temperature in September - Rexburg, ID
  • Average high temperature in September: 72.7°F

The warmest month (with the highest average high temperature) is July (84.2°F).
The month with the lowest average high temperature is December (26.6°F).

  • Average low temperature in September: 47.3°F

The month with the highest average low temperature is August (52.9°F).
The coldest month (with the lowest average low temperature) is January (12.7°F).

Average pressure in September
Rexburg, ID

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

The month with the highest atmospheric pressure is January (30.29"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).

Average wind speed in September
Rexburg, ID

Average wind speed in September - Rexburg, ID
  • Average wind speed in September: 6.3mph

The windiest month (with the highest average wind speed) is April (7.3mph).
The calmest month (with the lowest average wind speed) is January (4.3mph).

Average humidity in September
Rexburg, ID

Average humidity in September - Rexburg, ID
  • Average humidity in September: 43%

The month with the highest relative humidity is January (91%).
The month with the lowest relative humidity is August (38%).

Average rainfall in September
Rexburg, ID

Average rainfall in September - Rexburg, ID
  • Average rainfall in September: 0.91"

The wettest months (with the highest rainfall) are April and May (1.26").
The driest month (with the least rainfall) is July (0.39").

Average rainfall days in September
Rexburg, ID

Average rainfall days in September - Rexburg, ID
  • Average rainfall days in September: 9 days

The month with the highest number of rainy days is April (14.9 days).
The month with the least rainy days is July (6.3 days).

Average snowfall in September
Rexburg, ID

Average snowfall in September - Rexburg, ID
  • Average snowfall in September: 0.04"

The month with the highest snowfall is January (8.9").
The months with the least snowfall are June, July and August (0").

Average snowfall days in September
Rexburg, ID

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

The months with the highest number of snowfall days are January and February (18.1 days).
The months with the least snowfall days are July and August (0 days).

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

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

The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 9h and 0min).

  • Average sunshine in September: 10h and 0min

The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is January (Average sunshine: 4h and 30min).

Average sunshine days in September
Rexburg, ID

Average sunshine days in September - Rexburg, ID
  • Average sunshine days in September: 18 days

The month with the most sunshine days is July (20.6 days).
The month with the least sunshine days is February (8.8 days).

Average UV index in September
Rexburg, ID

Average UV index in September - Rexburg, ID
  • 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 and December (UV index 1).

Average cloud cover in September
Rexburg, ID

Average cloud cover in September - Rexburg, ID
  • Average cloud cover in September: 16

The months with the most cloud cover are January and February (Cloud cover 53).
The months with the least cloud cover are July and August (Cloud cover 11).

Average visibility in September
Rexburg, ID

Average visibility in September - Rexburg, 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).

Rexburg, Idaho, USA

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