August weather forecast
Lewistown, MT

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Weather in August

August in Lewistown experiences a mild decline in temperature, peaking at 78.1°F (25.6°C), indicating soft whispers of a nearing fall. Noticeably, rainfall inches up to 1.34, offering a slight relief from the dry spell. A declining trend in daylight and Sunshine hours reinstates the coming shift in seasons. The wind maintains a gentle stirring, and the atmosphere remains predominantly clear. A slight increase in humidity, while subtle, signals the paving path for the later rush of crispy autumn.

Temperature

August's advent in Lewistown notes a subtle adjustment in average high-temperature to a still moderately hot 78.1°F (25.6°C) from July. Lewistown in August observes a sharp transition from the daytime heat, falling to an average low of 54.5°F (12.5°C).

Humidity

With an average relative humidity of 47%, August is the least humid month.

Rainfall

In Lewistown, in August, it is raining for 10.5 days, with typically 1.34" (34mm) of accumulated precipitation. Throughout the year, there are 126.2 rainfall days, and 17.83" (453mm) of precipitation is accumulated.

Snowfall

July and August are months without snowfall.

Daylight

In Lewistown, the average length of the day in August is 14h and 10min.
On the first day of the month, sunrise is at 5:58 am and sunset at 8:49 pm. On the last day of August, sunrise is at 6:36 am and sunset at 7:58 pm MDT.

Sunshine

In Lewistown, the average sunshine in August is 11.4h.

UV index

The average daily maximum UV index in August is 5. A UV Index estimate of 3 to 5 represents a medium health hazard from unprotected exposure to Sun's UV rays for the ordinary person.
Note: A daily high UV index of 5 in August leads to these guidelines:
Make use of precautions - Suggestions to resist sunburn are communicated. During midday, the Sun's radiation is strongest, and it's advisable to reduce direct exposure. Counter UV radiation's ill effects with clothing designed for sun safety and UV-resistant eyewear.
Updated: Jul 30, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are August temperatures?

In August, in Lewistown, the average high-temperature is 78.1°F (25.6°C), and the average low-temperature is 54.5°F (12.5°C).

What is the least humid month?

August is the least humid month, with an average relative humidity of 47%.

What is the average humidity in August?

The average relative humidity in August is 47%.

How many days does it rain in August?

In Lewistown, in August, it is raining for 10.5 days, with typically 1.34" (34mm) of accumulated precipitation.

When it does not snow?

In Lewistown, snow does not fall in July and August.

Does it snow in August?

In Lewistown, in August, it doesn't snow. In September, it regularly snows.

How many hours of daylight does Lewistown have in August?

The average day length in August is 14h and 10min.

What time are sunrise and sunset in August?

In August, on the first day of the month, sunrise is at 5:58 am and sunset at 8:49 pm. On the last day of the month, sunrise is at 6:36 am and sunset at 7:58 pm MDT.

How long on average sun shines in August?

In August, the average sunshine duration is 11.4h.

What is the UV index reading in August in Lewistown?

The average daily maximum UV index in August is 5. A UV Index of 3 to 5 symbolizes a moderate vulnerability from unprotected exposure to 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 August
Lewistown, MT

Average temperature in August - Lewistown, MT
  • Average high temperature in August: 78.1°F

The warmest month (with the highest average high temperature) is July (78.8°F).
The months with the lowest average high temperature are February and December (29.1°F).

  • Average low temperature in August: 54.5°F

The month with the highest average low temperature is August (54.5°F).
The coldest month (with the lowest average low temperature) is February (15.3°F).

Average pressure in August
Lewistown, MT

Average pressure in August - Lewistown, MT
  • Average pressure in August: 29.9"Hg

The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).

Average wind speed in August
Lewistown, MT

Average wind speed in August - Lewistown, MT
  • Average wind speed in August: 7.4mph

The windiest months (with the highest average wind speed) are January, April and October (9.9mph).
The calmest month (with the lowest average wind speed) is August (7.4mph).

Average humidity in August
Lewistown, MT

Average humidity in August - Lewistown, MT
  • Average humidity in August: 47%

The month with the highest relative humidity is February (79%).
The month with the lowest relative humidity is August (47%).

Average rainfall in August
Lewistown, MT

Average rainfall in August - Lewistown, MT
  • Average rainfall in August: 1.34"

The wettest month (with the highest rainfall) is May (3.39").
The driest month (with the least rainfall) is December (0.71").

Average rainfall days in August
Lewistown, MT

Average rainfall days in August - Lewistown, MT
  • Average rainfall days in August: 10.5 days

The month with the highest number of rainy days is May (19.3 days).
The month with the least rainy days is January (5.4 days).

Average snowfall in August
Lewistown, MT

Average snowfall in August - Lewistown, MT
  • Average snowfall in August: 0"

The month with the highest snowfall is April (9.13").
The months with the least snowfall are July and August (0").

Average snowfall days in August
Lewistown, MT

Average snowfall days in August - Lewistown, MT
  • Average snowfall days in August: 0 days

The month with the highest number of snowfall days is February (15.2 days).
The months with the least snowfall days are July and August (0 days).

Average daylight in August /
Average sunshine in August
Lewistown, MT

Average daylight in August / Average sunshine in August - Lewistown, MT
  • Average daylight in August: 14h and 1min

The month with the longest days is June (Average daylight: 15h and 48min).
The month with the shortest days is December (Average daylight: 8h and 36min).

  • Average sunshine in August: 11h and 2min

The month with the most sunshine is July (Average sunshine: 11h and 48min).
The month with the least sunshine is February (Average sunshine: 5h and 30min).

Average sunshine days in August
Lewistown, MT

Average sunshine days in August - Lewistown, MT
  • Average sunshine days in August: 17.2 days

The month with the most sunshine days is September (19.3 days).
The month with the least sunshine days is April (8.3 days).

Average UV index in August
Lewistown, MT

Average UV index in August - Lewistown, MT
  • Average UV index in August: 5

The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, March, April, October, November and December (UV index 2).

Average cloud cover in August
Lewistown, MT

Average cloud cover in August - Lewistown, MT
  • Average cloud cover in August: 17

The month with the most cloud cover is February (Cloud cover 45).
The month with the least cloud cover is July (Cloud cover 16).

Average visibility in August
Lewistown, MT

Average visibility in August - Lewistown, MT
  • Average visibility in August: 6mi

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

Lewistown, Montana, USA

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