August weather forecast
Boise, ID

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The golden fall season in Boise, Idaho
The golden fall season in Boise, Idaho

Weather in August

August sees the last phase of summer in Boise, Idaho. Despite lingering heat, slow but gradual temperature declines commence. The daylight duration decreases slightly while relative humidity doesn’t see a significant change. With increased cloud cover, the sunshine duration reduces, yet the heat continues to sustain due to lower precipitation. A slight fall in temperature after July's peak sees a high of approximately 86.5°F (30.3°C).

Temperature

Boise experiences a recorded average high-temperature of a still tropical 86.5°F (30.3°C) in August, closely aligned with July's 87.8°F (31°C). In August, the nighttime temperature plummets remarkably from the daily apex to a steady average of 61.3°F (16.3°C).

Humidity

In Boise, the average relative humidity in August is 31%.

Rainfall

In Boise, in August, it is raining for 4.9 days, with typically 0.24" (6mm) of accumulated precipitation. Throughout the year, there are 116.8 rainfall days, and 15.08" (383mm) of precipitation is accumulated.

Snowfall

May through October are months without snowfall.

Daylight

In August, the average length of the day is 13h and 55min.
On the first day of the month, sunrise is at 6:35 am and sunset at 9:07 pm. On the last day of August, sunrise is at 7:08 am and sunset at 8:21 pm MDT.

Sunshine

The average sunshine in August is 11.4h.

UV index

In Boise, the average daily maximum UV index in August is 5. A UV Index value of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to UV radiation for average individuals.
Note: In August, an average UV index of 5 transforms into the following instructions:
Make use of precautions - Suggestions to resist sunburn are communicated. Limiting sun exposure during midday hours helps in reducing the harmful effects of UV radiation. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes.
Updated: Aug 26, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How hot does it get in August?

The high-temperature, in August, in Boise, records 86.5°F (30.3°C), while the low-temperature is 61.3°F (16.3°C).

What is the average humidity in August?

In Boise, the average relative humidity in August is 31%.

How many days does it rain in August?

In Boise, during August, the rain falls for 4.9 days and regularly aggregates up to 0.24" (6mm) of precipitation.

When it does not snow?

May through October are months without snowfall.

What is the average length of the day in August?

In Boise, the average day length in August is 13h and 55min.

When are sunrise and sunset in August?

In August, on the first day of the month, sunrise is at 6:35 am and sunset at 9:07 pm. On the last day of the month, sunrise is at 7:08 am and sunset at 8:21 pm MDT.

How many hours of sunshine does Boise have in August?

The average sunshine duration in August is 11.4h.

How high is the UV index in August?

In Boise, the average daily maximum UV index in August is 5. A UV Index reading of 3 to 5 represents a moderate health threat from unsafe exposure to Sun's UV rays.
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
Boise, ID

Average temperature in August - Boise, ID
  • Average high temperature in August: 86.5°F

The warmest month (with the highest average high temperature) is July (87.8°F).
The month with the lowest average high temperature is December (34.7°F).

  • Average low temperature in August: 61.3°F

The month with the highest average low temperature is August (61.3°F).
The coldest month (with the lowest average low temperature) is December (23.2°F).

Average pressure in August
Boise, ID

Average pressure in August - Boise, ID
  • Average pressure in August: 29.91"Hg

The month with the highest atmospheric pressure is January (30.25"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).

Average wind speed in August
Boise, ID

Average wind speed in August - Boise, ID
  • Average wind speed in August: 5.4mph

The windiest month (with the highest average wind speed) is April (7.1mph).
The calmest month (with the lowest average wind speed) is January (5.2mph).

Average humidity in August
Boise, ID

Average humidity in August - Boise, ID
  • Average humidity in August: 31%

The month with the highest relative humidity is January (80%).
The month with the lowest relative humidity is July (30%).

Average rainfall in August
Boise, ID

Average rainfall in August - Boise, ID
  • Average rainfall in August: 0.24"

The wettest month (with the highest rainfall) is March (2.2").
The driest month (with the least rainfall) is July (0.2").

Average rainfall days in August
Boise, ID

Average rainfall days in August - Boise, ID
  • Average rainfall days in August: 4.9 days

The month with the highest number of rainy days is March (16.2 days).
The month with the least rainy days is July (4.5 days).

Average snowfall in August
Boise, ID

Average snowfall in August - Boise, ID
  • Average snowfall in August: 0"

The month with the highest snowfall is December (6.65").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in August
Boise, ID

Average snowfall days in August - Boise, ID
  • Average snowfall days in August: 0 days

The month with the highest number of snowfall days is December (9.2 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in August /
Average sunshine in August
Boise, ID

Average daylight in August / Average sunshine in August - Boise, ID
  • Average daylight in August: 13h and 5min

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 August: 11h and 2min

The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 5h and 30min).

Average sunshine days in August
Boise, ID

Average sunshine days in August - Boise, ID
  • Average sunshine days in August: 21.7 days

The month with the most sunshine days is July (23.6 days).
The month with the least sunshine days is March (12.1 days).

Average UV index in August
Boise, ID

Average UV index in August - Boise, ID
  • Average UV index in August: 5

The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average cloud cover in August
Boise, ID

Average cloud cover in August - Boise, ID
  • Average cloud cover in August: 9

The month with the most cloud cover is December (Cloud cover 42).
The month with the least cloud cover is July (Cloud cover 8).

Average visibility in August
Boise, ID

Average visibility in August - Boise, ID
  • Average visibility in August: 6mi

The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).

Boise, Idaho, USA

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