August weather forecast
Grand Junction, CO

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The scenic Grand Junction in Colorado with the iconic Colorado River and high hills nearby
The scenic Grand Junction in Colorado with the iconic Colorado River and high hills nearby

Weather in August

August is a month of mild changes for Grand Junction. The weather accommodates a mild decrease in highest temperature to 84.2°F (29°C), still providing ample warmth. The humidity remains low despite being peak summer month, with rain in moderation. A decrease in daylight hours subtly hints at the impending change in seasons. Despite the slight decrease in sunlight, August offers the year's highest visibility, inviting residents and visitors to soak in the natural scenery.

Temperature

August's commencement is accompanied by an average high-temperature of a warm 84.2°F (29°C), diverging marginally from July's 86.9°F (30.5°C). The nighttime temperature during August exhibits a clear drop from daytime highs, settling at a moderate 58.8°F (14.9°C).

Humidity

In August, the average relative humidity is 38%.

Rainfall

In Grand Junction, in August, it is raining for 8.7 days, with typically 0.75" (19mm) of accumulated precipitation. Throughout the year, there are 93.6 rainfall days, and 8.46" (215mm) of precipitation is accumulated.

Snowfall

May through September are months without snowfall.

Daylight

In Grand Junction, the average length of the day in August is 13h and 39min.
On the first day of August, sunrise is at 6:15 am and sunset at 8:25 pm. On the last day of the month, sunrise is at 6:42 am and sunset at 7:45 pm MDT.

Sunshine

The average sunshine in August is 11.9h.

UV index

June through August, with an average maximum UV index of 6, are months with the highest UV index. A UV Index estimate of 6 to 7 represents a high health hazard from unsafe exposure to UV radiation for ordinary individuals.
Note: The maximum UV index of 6 during August translates into these guidelines:
Avoid overexposure. Fair-skinned individuals can burn in under 20 minutes. Between 10 a.m. and 4 p.m., the Sun's UV radiation is at its peak. Limit your exposure to direct sunlight during these hours. On sunny days, it's ideal to wear sunglasses that filter out UVA and UVB rays.

Frequently asked questions

How hot does it get in August?

In August, the average high-temperature and low-temperature are 84.2°F (29°C) and 58.8°F (14.9°C) respectively.

What is the average humidity in August?

In Grand Junction, the average relative humidity in August is 38%.

How many days does it rain in August?

In Grand Junction, in August, it is raining for 8.7 days, with typically 0.75" (19mm) of accumulated precipitation.

When it does not snow?

May through September are months without snowfall.

What is the average length of the day in August?

In August, the average day length is 13h and 39min.

What time are sunrise and sunset in August?

On the first day of August, sunrise is at 6:15 am and sunset at 8:25 pm. On the last day of the month, sunrise is at 6:42 am and sunset at 7:45 pm MDT.

How long on average sun shines in August?

The average sunshine duration in August is 11.9h.

What is the month with the highest UV index in Grand Junction?

June through August, with an average maximum UV index of 6, are months with the highest UV index.

How high is the UV index in August?

In August, the average daily maximum UV index is 6. A UV Index estimate of 6 to 7 represents a high health risk from exposure to the Sun's 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
Grand Junction, CO

Average temperature in August - Grand Junction, CO
  • Average high temperature in August: 84.2°F

The warmest month (with the highest average high temperature) is July (86.9°F).
The month with the lowest average high temperature is January (34.9°F).

  • Average low temperature in August: 58.8°F

The month with the highest average low temperature is July (60.4°F).
The coldest month (with the lowest average low temperature) is January (18.3°F).

Average pressure in August
Grand Junction, CO

Average pressure in August - Grand Junction, CO
  • Average pressure in August: 30"Hg

The month with the highest atmospheric pressure is January (30.27"Hg).
The months with the lowest atmospheric pressure are May and June (29.9"Hg).

Average wind speed in August
Grand Junction, CO

Average wind speed in August - Grand Junction, CO
  • Average wind speed in August: 5.9mph

The windiest month (with the highest average wind speed) is June (7.5mph).
The calmest month (with the lowest average wind speed) is January (4.2mph).

Average humidity in August
Grand Junction, CO

Average humidity in August - Grand Junction, CO
  • Average humidity in August: 38%

The month with the highest relative humidity is January (78%).
The month with the lowest relative humidity is June (29%).

Average rainfall in August
Grand Junction, CO

Average rainfall in August - Grand Junction, CO
  • Average rainfall in August: 0.75"

The wettest month (with the highest rainfall) is March (1.06").
The driest month (with the least rainfall) is June (0.51").

Average rainfall days in August
Grand Junction, CO

Average rainfall days in August - Grand Junction, CO
  • Average rainfall days in August: 8.7 days

The month with the highest number of rainy days is March (10.4 days).
The month with the least rainy days is November (5.5 days).

Average snowfall in August
Grand Junction, CO

Average snowfall in August - Grand Junction, CO
  • Average snowfall in August: 0"

The month with the highest snowfall is December (3.74").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in August
Grand Junction, CO

Average snowfall days in August - Grand Junction, CO
  • Average snowfall days in August: 0 days

The month with the highest number of snowfall days is January (7.9 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

Average daylight in August /
Average sunshine in August
Grand Junction, CO

Average daylight in August / Average sunshine in August - Grand Junction, CO
  • Average daylight in August: 13h and 4min

The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).

  • Average sunshine in August: 11h and 5min

The month with the most sunshine is June (Average sunshine: 12h and 0min).
The month with the least sunshine is January (Average sunshine: 6h and 18min).

Average sunshine days in August
Grand Junction, CO

Average sunshine days in August - Grand Junction, CO
  • Average sunshine days in August: 16.6 days

The month with the most sunshine days is November (22.3 days).
The month with the least sunshine days is February (15.8 days).

Average UV index in August
Grand Junction, CO

Average UV index in August - Grand Junction, CO
  • Average UV index in August: 6

The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average cloud cover in August
Grand Junction, CO

Average cloud cover in August - Grand Junction, CO
  • Average cloud cover in August: 12

The month with the most cloud cover is January (Cloud cover 31).
The months with the least cloud cover are June and September (Cloud cover 11).

Average visibility in August
Grand Junction, CO

Average visibility in August - Grand Junction, CO
  • 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).

Grand Junction, Colorado, USA

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