Boulder, Colorado Weather by Month
Boulder, Colorado experiences four distinct seasons, with cold and snowy winters, mild spring weather, warm summers, and cool autumns. March is the snowiest month in the supplied data, while July is the warmest month. May has the highest rainfall, while June has the longest daylight hours at about 15 hours per day.
The following monthly guide uses the temperature, rainfall, snowfall, rainy-day, and daylight data you provided.
Boulder, Colorado Weather by Month
You can click the image below to view the full-size weather chart for Boulder, CO.
January – Cold and Snowy Winter Weather
Average high: 46°F (8°C)
Average low: 21°F (-6°C)
Rainfall: 0.7 inches
Rainy days: 3
Snowfall: 10.91 inches
Daylight: 9.5 hours
January is one of the coldest months in Boulder, with average daytime temperatures around 46°F and nighttime temperatures falling to about 21°F. Snow is a major part of the winter climate, with approximately 10.91 inches of snowfall in the supplied data.
Rainfall is relatively low at about 0.7 inches, while much of the winter precipitation can come as snow. With only 9.5 hours of daylight, January has some of the shortest days of the year.
Best for:
- Winter scenery
- Snow activities
- Indoor attractions
- Quiet winter visits
February – Cold, Snowy, and Increasing Daylight
Average high: 48°F (9°C)
Average low: 23°F (-5°C)
Rainfall: 1.0 inch
Rainy days: 4
Snowfall: 14.56 inches
Daylight: 10.5 hours
February remains cold and snowy in Boulder. Average highs reach about 48°F, while nighttime temperatures average around 23°F. The supplied data shows about 14.56 inches of snowfall, making February one of the snowiest months of the year.
Rainfall increases slightly to 1.0 inch, while daylight grows to about 10.5 hours. Winter conditions can still be quite pronounced, especially during snow events.
Best for:
- Snowy landscapes
- Winter photography
- Indoor attractions
- Cozy mountain trips
March – Snowiest Month of the Year
Average high: 55°F (13°C)
Average low: 28°F (-2°C)
Rainfall: 1.9 inches
Rainy days: 5
Snowfall: 15.89 inches
Daylight: 12 hours
March brings a noticeable warming trend, with average highs reaching 55°F. However, nights remain cold at around 28°F. According to the supplied snowfall data, March is the snowiest month, with approximately 15.89 inches of snow.
Rainfall also rises to about 1.9 inches, and Boulder receives around 12 hours of daylight. Weather can change quickly during March, with mild afternoons followed by cold or snowy periods.
Best for:
- Late-season snow
- Winter-to-spring scenery
- Hiking on milder days
- Photography
April – Mild Days and Spring Precipitation
Average high: 63°F (17°C)
Average low: 36°F (2°C)
Rainfall: 2.8 inches
Rainy days: 6
Snowfall: 12.64 inches
Daylight: 13 hours
April brings noticeably milder temperatures to Boulder, with average highs around 63°F and lows near 36°F. Spring precipitation becomes more significant, with about 2.8 inches of rainfall.
Despite the warmer temperatures, snow is still possible, and the supplied data shows approximately 12.64 inches of snowfall. With 13 hours of daylight, April offers more time for outdoor activities.
Best for:
- Spring hiking
- Scenic drives
- Exploring parks
- Outdoor photography
May – Mild, Wet, and Green
Average high: 72°F (22°C)
Average low: 43°F (6°C)
Rainfall: 3.2 inches
Rainy days: 8
Snowfall: 1.91 inches
Daylight: 14.5 hours
May is one of the wettest months in Boulder, with about 3.2 inches of rainfall and 8 rainy days in the supplied data. Average highs climb to a comfortable 72°F, while nighttime temperatures average around 43°F.
Snowfall drops dramatically to about 1.91 inches as spring takes hold. With 14.5 hours of daylight, May is an excellent month for spending time outdoors.
Best for:
- Hiking
- Parks and trails
- Spring scenery
- Outdoor activities
June – Warm, Sunny, and Long Days
Average high: 82°F (28°C)
Average low: 52°F (11°C)
Rainfall: 1.9 inches
Rainy days: 6
Snowfall: 0 inches
Daylight: 15 hours
June marks the beginning of warm summer weather in Boulder. Average highs reach about 82°F, while lows remain comfortable at around 52°F. Snowfall falls to zero in the supplied data.
Rainfall is around 1.9 inches, and June has the longest daylight of the year at approximately 15 hours. The combination of warm temperatures and long days makes June especially appealing for outdoor recreation.
Best for:
- Hiking
- Cycling
- Camping
- Mountain exploration
July – Warmest Month of the Year
Average high: 88°F (31°C)
Average low: 57°F (14°C)
Rainfall: 1.9 inches
Rainy days: 6
Snowfall: 0 inches
Daylight: 14.5 hours
July is the warmest month in Boulder based on the supplied temperature data, with average highs around 88°F and lows near 57°F. Snow is absent, while rainfall remains relatively modest at about 1.9 inches.
The city receives approximately 14.5 hours of daylight, providing plenty of time for hiking, sightseeing, and other outdoor activities. Warm afternoons can be hot, so early morning and evening are often more comfortable for strenuous activities.
Best for:
- Hiking
- Cycling
- Camping
- Outdoor adventures
August – Warm Summer Weather
Average high: 86°F (30°C)
Average low: 55°F (13°C)
Rainfall: 1.6 inches
Rainy days: 5
Snowfall: 0 inches
Daylight: 14 hours
August remains warm in Boulder, although temperatures are slightly lower than in July. Average highs reach about 86°F, with nighttime temperatures around 55°F.
Rainfall is approximately 1.6 inches, and there is no snowfall in the supplied data. Boulder receives around 14 hours of daylight, keeping summer days long and favorable for outdoor activities.
Best for:
- Hiking
- Mountain trips
- Camping
- Outdoor sightseeing
September – Warm Days and Cooler Nights
Average high: 79°F (26°C)
Average low: 48°F (9°C)
Rainfall: 1.9 inches
Rainy days: 4
Snowfall: 0.96 inches
Daylight: 12.5 hours
September brings the beginning of autumn, with temperatures becoming more comfortable. Average highs are around 79°F, while nighttime temperatures cool to approximately 48°F.
Rainfall is about 1.9 inches, and the supplied data records only 0.96 inches of snowfall. With 12.5 hours of daylight, September offers a pleasant balance between warm days and cooler evenings.
Best for:
- Hiking
- Fall scenery
- Scenic drives
- Outdoor sightseeing
October – Cool Autumn Weather
Average high: 66°F (19°C)
Average low: 37°F (3°C)
Rainfall: 1.4 inches
Rainy days: 4
Snowfall: 5.33 inches
Daylight: 11 hours
October brings cooler autumn conditions to Boulder. Average daytime temperatures reach about 66°F, while nighttime temperatures fall to around 37°F.
Rainfall decreases to approximately 1.4 inches, but snowfall increases to about 5.33 inches in the supplied data. With 11 hours of daylight, October offers comfortable conditions for exploring Boulder before winter becomes more prominent.
Best for:
- Fall foliage
- Hiking
- Photography
- Scenic mountain trips
November – Cold and Increasingly Snowy
Average high: 54°F (12°C)
Average low: 28°F (-2°C)
Rainfall: 1.2 inches
Rainy days: 3
Snowfall: 12.85 inches
Daylight: 10 hours
November marks a return to colder weather in Boulder. Average highs reach about 54°F, while nighttime temperatures average around 28°F. Snowfall increases considerably to approximately 12.85 inches.
Rainfall remains relatively low at about 1.2 inches, while daylight decreases to around 10 hours. Winter conditions can begin to establish themselves during this month.
Best for:
- Early winter scenery
- Snow photography
- Quiet mountain visits
- Indoor attractions
December – Cold, Snowy, and Short Days
Average high: 46°F (8°C)
Average low: 21°F (-6°C)
Rainfall: 0.8 inches
Rainy days: 3
Snowfall: 12.66 inches
Daylight: 9.5 hours
December is another cold and snowy month in Boulder, with average highs around 46°F and lows near 21°F. The supplied data shows approximately 12.66 inches of snowfall, making winter conditions a major feature of the month.
Rainfall is only about 0.8 inches, while daylight falls to 9.5 hours. Cold temperatures and frequent snow make December feel distinctly wintry.
Best for:
- Winter scenery
- Snow activities
- Holiday atmosphere
- Indoor attractions
Boulder, Colorado Weather by Month Table
| Month | Avg High °F (°C) | Avg Low °F (°C) | Rainfall (inches) | Sun (hrs/day) | Snowfall (inches) |
|---|---|---|---|---|---|
| January | 46°F (8°C) | 21°F (-6°C) | 0.7 | 9.5 | 10.91 |
| February | 48°F (9°C) | 23°F (-5°C) | 1.0 | 10.5 | 14.56 |
| March | 55°F (13°C) | 28°F (-2°C) | 1.9 | 12.0 | 15.89 |
| April | 63°F (17°C) | 36°F (2°C) | 2.8 | 13.0 | 12.64 |
| May | 72°F (22°C) | 43°F (6°C) | 3.2 | 14.5 | 1.91 |
| June | 82°F (28°C) | 52°F (11°C) | 1.9 | 15.0 | 0 |
| July | 88°F (31°C) | 57°F (14°C) | 1.9 | 14.5 | 0 |
| August | 86°F (30°C) | 55°F (13°C) | 1.6 | 14.0 | 0 |
| September | 79°F (26°C) | 48°F (9°C) | 1.9 | 12.5 | 0.96 |
| October | 66°F (19°C) | 37°F (3°C) | 1.4 | 11.0 | 5.33 |
| November | 54°F (12°C) | 28°F (-2°C) | 1.2 | 10.0 | 12.85 |
| December | 46°F (8°C) | 21°F (-6°C) | 0.8 | 9.5 | 12.66 |
Boulder Weather by Month: Quick Overview
Boulder has a wide range of weather throughout the year. January and December are among the coldest months, with average lows around 21°F, while July is the warmest month, reaching an average high of 88°F.
March is the snowiest month in the supplied data, with approximately 15.89 inches of snowfall. May is the wettest month, receiving about 3.2 inches of rainfall and 8 rainy days. June has the longest daylight, at approximately 15 hours per day.
For warm-weather outdoor activities, June through September are among the most favorable months. For snow and winter scenery, December through March offer the strongest winter conditions.
20 FAQs About Boulder, Colorado Weather
1. What is the weather like in Boulder, Colorado?
Boulder has four distinct seasons. Winters are cold and snowy, springs are mild and wetter, summers are warm and relatively dry, and autumn brings cooler temperatures and increasing chances of snow.
2. What is the coldest month in Boulder?
January and December are among the coldest months. Average lows are around 21°F (-6°C), while average highs are about 46°F (8°C).
3. What is the warmest month in Boulder?
July is the warmest month, with an average high of about 88°F (31°C) and an average low of approximately 57°F (14°C).
4. Does it snow in Boulder, Colorado?
Yes. Snow is common during the colder months, particularly from late fall through early spring. March has the highest snowfall in the supplied data.
5. What is the snowiest month in Boulder?
March is the snowiest month, with approximately 15.89 inches of snowfall in the supplied data.
6. How much snow does Boulder get in January?
January receives approximately 10.91 inches of snowfall based on the supplied data. Snow can occur throughout the month, particularly during cold weather systems.
7. Does it snow in Boulder in April?
Yes. Although April is much warmer than winter, snowfall can still occur. The supplied data shows approximately 12.64 inches of snowfall in April.
8. What is the rainiest month in Boulder?
May is the rainiest month in the supplied data, with approximately 3.2 inches of rainfall and 8 rainy days.
9. How much rain does Boulder get in summer?
Summer rainfall is relatively moderate. June, July, and September each have about 1.9 inches, while August has approximately 1.6 inches in the supplied data.
10. What is Boulder like in January?
January is cold and snowy, with an average high of 46°F (8°C) and an average low of 21°F (-6°C). It also has only about 9.5 hours of daylight.
11. What is Boulder like in March?
March is a transitional month. Average highs reach about 55°F (13°C), while lows remain near 28°F (-2°C). It is also the snowiest month in the supplied data.
12. What is Boulder like in May?
May is mild and relatively wet. Average temperatures range from about 43°F (6°C) at night to 72°F (22°C) during the day. It also has the highest rainfall in the supplied data.
13. What is Boulder like in June?
June is warm and ideal for outdoor activities. The average high is approximately 82°F (28°C), and Boulder receives about 15 hours of daylight, the most of any month.
14. What is Boulder like in July?
July is the warmest month, with an average high of 88°F (31°C). Nights are considerably cooler, averaging about 57°F (14°C), making evenings more comfortable.
15. What is Boulder like in August?
August remains warm, with an average high of 86°F (30°C) and an average low of 55°F (13°C). Rainfall is relatively moderate at about 1.6 inches.
16. What is Boulder like in September?
September brings comfortable late-summer and early-autumn weather. Average highs are around 79°F (26°C), while lows fall to about 48°F (9°C).
17. What is Boulder like in October?
October is cooler, with average highs of 66°F (19°C) and lows of 37°F (3°C). Snowfall begins to become more significant, with about 5.33 inches in the supplied data.
18. How much daylight does Boulder get?
Daylight varies considerably throughout the year. Boulder gets about 9.5 hours per day in January and December, compared with approximately 15 hours in June.
19. What are the best months to visit Boulder for outdoor activities?
June through September are generally excellent for outdoor activities because of warm temperatures, long daylight hours, and no significant snowfall in the supplied data. July and August are particularly warm.
20. What is the best month to visit Boulder, Colorado?
The best month depends on what you want to do. June and September offer a good balance of comfortable temperatures and outdoor-friendly conditions, while July and August are better for those who prefer warmer summer weather. For snow activities, January through March are better choices.
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