July weather forecast
Boulder, CO

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The old building of the University of Colorado in Boulder, Colorado
The old building of the University of Colorado in Boulder, Colorado

Weather in July

July is the peak of summer in Boulder, offering the highest temperatures of the year. The city's atmosphere becomes infused with summer vibes due to high temperatures, hitting highs around 80.4°F (26.9°C) and lows around 55.2°F (12.9°C). Despite the temperature surge, a noteworthy amount of rain (averaging about 1.89" (48mm)) provides a refreshing break. Though August will carry on the summer warmth, it also introduces slight cooling as the season begins to wind down. Therefore, July, with its high temperatures and frequent rainfall, provides a unique blend of weather conditions.

Temperature

July is the month that records the highest temperatures, with averages ranging from a high of 80.4°F (26.9°C) to a low of 55.2°F (12.9°C).

Humidity

The average relative humidity in July is 48%.

Rainfall

In Boulder, in July, it is raining for 17.8 days, with typically 1.89" (48mm) of accumulated precipitation. In Boulder, Colorado, during the entire year, the rain falls for 117.3 days and collects up to 14.17" (360mm) of precipitation.

Snowfall

In Boulder, snow does not fall in June through September.

Daylight

In July, the average length of the day is 14h and 41min.
On the first day of the month, sunrise is at 5:36 am and sunset at 8:33 pm. On the last day of July, sunrise is at 5:59 am and sunset at 8:15 pm MDT.

Sunshine

The months with the most sunshine are June and July, with an average of 11.7h of sunshine.

UV index

June through August, with an average maximum UV index of 5, are months with the highest UV index. A UV Index value of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for the average person.
Note: The maximum daily UV index of 5 in July converts into the following recommendations:
Exercise caution. The susceptibility of light skin individuals to burns is less than 30 minutes. It's crucial to reduce time in the direct Sun around mid-day due to the intense solar radiation. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly.

Frequently asked questions

What time of the year is the hottest?

July is the warmest month, exhibiting average temperatures of 80.4°F (26.9°C) at the peak and 55.2°F (12.9°C) at the base.

What are July temperatures?

An average high-temperature, in July, in Boulder, is 80.4°F (26.9°C) and the average low-temperature is 55.2°F (12.9°C).

What is the average humidity in July?

The average relative humidity in July is 48%.

How much does it rain in July?

In July, the rain falls for 17.8 days. Throughout July, 1.89" (48mm) of precipitation is accumulated.

When it does not snow in Boulder?

June through September are months without snowfall.

How many hours of daylight does Boulder have in July?

The average day length in July is 14h and 41min.

When are sunrise and sunset in July in Boulder?

In July, on the first day of the month, sunrise is at 5:36 am and sunset at 8:33 pm. On the last day of the month, sunrise is at 5:59 am and sunset at 8:15 pm MDT.

What is the month with the most sunshine?

The months with the most sunshine are June and July, with an average of 11.7h of sunshine.

How long on average sun shines in July?

In Boulder, the average sunshine duration in July is 11.7h.

What is the month with the highest UV index?

June through August, with an average maximum UV index of 5, are months with the highest UV index.

What is the UV index reading in July?

In July, the average daily maximum UV index 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 July
Boulder, CO

Average temperature in July - Boulder, CO
  • Average high temperature in July: 80.4°F

The warmest month (with the highest average high temperature) is July (80.4°F).
The month with the lowest average high temperature is December (35.2°F).

  • Average low temperature in July: 55.2°F

The month with the highest average low temperature is July (55.2°F).
The coldest month (with the lowest average low temperature) is February (18°F).

Average pressure in July
Boulder, CO

Average pressure in July - Boulder, CO
  • Average pressure in July: 30.01"Hg

The month with the highest atmospheric pressure is January (30.15"Hg).
The months with the lowest atmospheric pressure are April, May and June (29.92"Hg).

Average wind speed in July
Boulder, CO

Average wind speed in July - Boulder, CO
  • Average wind speed in July: 5.7mph

The windiest month (with the highest average wind speed) is January (7.3mph).
The calmest months (with the lowest average wind speed) are May, July, August and September (5.7mph).

Average humidity in July
Boulder, CO

Average humidity in July - Boulder, CO
  • Average humidity in July: 48%

The month with the highest relative humidity is February (70%).
The months with the lowest relative humidity are June, August and September (45%).

Average rainfall in July
Boulder, CO

Average rainfall in July - Boulder, CO
  • Average rainfall in July: 1.89"

The wettest month (with the highest rainfall) is May (2.48").
The driest month (with the least rainfall) is January (0.39").

Average rainfall days in July
Boulder, CO

Average rainfall days in July - Boulder, CO
  • Average rainfall days in July: 17.8 days

The month with the highest number of rainy days is July (17.8 days).
The month with the least rainy days is November (3.3 days).

Average snowfall in July
Boulder, CO

Average snowfall in July - Boulder, CO
  • Average snowfall in July: 0"

The month with the highest snowfall is April (7.76").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in July
Boulder, CO

Average snowfall days in July - Boulder, CO
  • Average snowfall days in July: 0 days

The month with the highest number of snowfall days is February (10.3 days).
The months with the least snowfall days are June, July and August (0 days).

Average daylight in July /
Average sunshine in July
Boulder, CO

Average daylight in July / Average sunshine in July - Boulder, CO
  • Average daylight in July: 14h and 4min

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

  • Average sunshine in July: 11h and 4min

The months with the most sunshine are June and July (Average sunshine: 11h and 42min).
The month with the least sunshine is February (Average sunshine: 6h and 36min).

Average sunshine days in July
Boulder, CO

Average sunshine days in July - Boulder, CO
  • Average sunshine days in July: 9.9 days

The month with the most sunshine days is January (22.2 days).
The month with the least sunshine days is July (9.9 days).

Average UV index in July
Boulder, CO

Average UV index in July - Boulder, CO
  • Average UV index in July: 5

The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average cloud cover in July
Boulder, CO

Average cloud cover in July - Boulder, CO
  • Average cloud cover in July: 20

The months with the most cloud cover are April and May (Cloud cover 28).
The month with the least cloud cover is September (Cloud cover 16).

Average visibility in July
Boulder, CO

Average visibility in July - Boulder, CO
  • Average visibility in July: 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).

Boulder, Colorado, USA

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