April weather forecast
Boulder, CO

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

Weather in April

With the arrival of April, Boulder embraces the full potential of spring, leaving behind the heavy snowfall of March. This period of the year is typified by a further rise in temperature and more frequent rainfall, tallying at approximately 1.65" (42mm). The spirits of April bloom as the city garners more sunlight and increased daylight hours. Come May, the conditions become progressively warmer and more conducive for outdoor activities. Therefore, April serves as a crucial period ushering in the lively and animated aura of spring.

Temperature

April's arrival brings a modest temperature shift, moving from a chilly 46.4°F (8°C) in March to a fresh 52.3°F (11.3°C). Boulder witnesses a consistent, sharp contrast from the daytime highs, with an average low-temperature of 30.7°F (-0.7°C) throughout April.

Humidity

The average relative humidity in April is 58%.

Rainfall

In Boulder, in April, it is raining for 12.3 days, with typically 1.65" (42mm) of accumulated precipitation. Throughout the year, there are 117.3 rainfall days, and 14.17" (360mm) of precipitation is accumulated.

Snowfall

January through May, October through December are months with snowfall in Boulder. The month with the most snowfall in Boulder is April, when snow falls for 4.9 days and typically aggregates up to 7.76" (197mm) of snow.

Daylight

The average length of the day in April in Boulder is 13h and 18min.
On the first day of April, sunrise is at 6:43 am and sunset at 7:25 pm. On the last day of the month, sunrise is at 6:01 am and sunset at 7:55 pm MDT.

Sunshine

In Boulder, the average sunshine in April is 10.3h.

UV index

The average daily maximum UV index in April is 3. A UV Index estimate of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for average individuals.
Note: The daily high UV index of 3 in April translates into this advice:
Take precautions. Light skin individuals may get burned in less than 30 minutes. Direct exposure to the Sun during its peak hours around mid-day should be minimized for safety. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection. Be mindful! The reflection from snow can increase the Sun's UV radiation nearly twice.
Updated: Feb 10, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are April temperatures in Boulder?

In Boulder, in April, the average high-temperature is 52.3°F (11.3°C), and the average low-temperature is 30.7°F (-0.7°C).

What is the average humidity in April in Boulder?

In Boulder, Colorado, the average relative humidity in April is 58%.

How much does it rain in Boulder in April?

In April, in Boulder, Colorado, the rain falls for 12.3 days. Throughout April, 1.65" (42mm) of precipitation is accumulated.

What is the snowiest month in Boulder?

The month with the most snowfall in Boulder, Colorado, is April, when snow falls for 4.9 days and typically aggregates up to 7.76" (197mm) of snow.

How many days does it snow in April in Boulder?

In Boulder, Colorado, in April, during 4.9 snowfall days, 7.76" (197mm) of snow is typically accumulated.

What is the average length of the day in April in Boulder?

In April, the average day length in Boulder, Colorado, is 13h and 18min.

What time are sunrise and sunset in April in Boulder?

In April, on the first day of the month, sunrise is at 6:43 am and sunset at 7:25 pm. On the last day of the month, in Boulder, Colorado, sunrise is at 6:01 am and sunset at 7:55 pm MDT.

How many hours of sunshine does Boulder have in April?

In Boulder, the average sunshine duration in April is 10.3h.

What is the UV index reading in April in Boulder?

In Boulder, the average daily maximum UV index in April is 3. A UV Index estimate of 3 to 5 represents a medium health risk from unprotected exposure to 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 April
Boulder, CO

Average temperature in April - Boulder, CO
  • Average high temperature in April: 52.3°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 April: 30.7°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 April
Boulder, CO

Average pressure in April - Boulder, CO
  • Average pressure in April: 29.92"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 April
Boulder, CO

Average wind speed in April - Boulder, CO
  • Average wind speed in April: 6.6mph

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 April
Boulder, CO

Average humidity in April - Boulder, CO
  • Average humidity in April: 58%

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 April
Boulder, CO

Average rainfall in April - Boulder, CO
  • Average rainfall in April: 1.65"

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 April
Boulder, CO

Average rainfall days in April - Boulder, CO
  • Average rainfall days in April: 12.3 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 April
Boulder, CO

Average snowfall in April - Boulder, CO
  • Average snowfall in April: 7.76"

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 April
Boulder, CO

Average snowfall days in April - Boulder, CO
  • Average snowfall days in April: 4.9 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 April /
Average sunshine in April
Boulder, CO

Average daylight in April / Average sunshine in April - Boulder, CO
  • Average daylight in April: 13h and 2min

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 April: 10h and 2min

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 April
Boulder, CO

Average sunshine days in April - Boulder, CO
  • Average sunshine days in April: 13.2 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 April
Boulder, CO

Average UV index in April - Boulder, CO
  • Average UV index in April: 3

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 April
Boulder, CO

Average cloud cover in April - Boulder, CO
  • Average cloud cover in April: 28

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 April
Boulder, CO

Average visibility in April - Boulder, CO
  • Average visibility in April: 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

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location