Boulder, CO weather and climate in 2024
Day
22 °C
Night
6 °C
Sea
0 °C
Precipitation
69 mm
in month
Rainy days
11 days
in month
Daylight
14 hours
average
Sunshine
9 hours
average
Humidity
51 %
Day
22 °C
Night
6 °C
Sea
0 °C
Precipitation
69 mm
in month
Rainy days
11 days
in month
Daylight
14 hours
average
Sunshine
9 hours
average
Humidity
51 %
Overview: Boulder, CO
Weather charts for Boulder, CO
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Weather overview for Boulder, CO
Weather overview
Boulder, Colorado, a city at the foothills of the magnificent Rocky Mountains, experiences a semi-arid climate with four distinct seasons and significant temperature fluctuations. The warm and dry summer months are followed by cool, crisp autumns. Winters, though cold, are generally mild with periodic snow, and the spring steadily warms up with occasional rain showers. Precipitation varies through the year, with the wettest season occurring in the spring. On any given day, Boulder's weather can be as dynamic as its landscape, making it a place where one may experience multiple seasons within a 24-hour span.
January weather
January in Boulder entails chilly nights averaging around -7 °C (19 °F) and daytime temperatures reaching up to 8 °C (46 °F). The skies bless residents with approximately 7 hours of sunshine, but don't be fooled, as there are about 6 of precipitation to be prepared for.
February weather
With the height of winter, February's nightly lows average around -6 °C (21 °F), while daytime temperatures slightly increase to an average of 8 °C (47 °F). A sprinkle of 7 of precipitation and an average wind speed of 3 bring a crisp feel to the weather.
March weather
March sees an uptick in daytime warmth with high temperatures averaging 13 °C (55 °F), notwithstanding the remaining coolness of the night with an average low of -3 °C (27 °F). Rainfall is more common this month, with 9 of precipitation and ample wind at 4.
April weather
April displays a full swing into spring with more consistent days of sun and daytime highs hitting an average of 17 °C (62 °F). The night temperature rises to an average of 1 °C (34 °F), and the weather can be quite moist with around 10 of wet weather to expect.
May weather
The merry month of May comes with a gentler touch of warmth, daytime highs average at a cozy 22 °C (72 °F), while nights remain mild with an average temperature of 6 °C (44 °F). This month is characterized by the highest amount of rainfall for the year, averaging 69 mm (2.72 in) over 11.
June weather
June ushers in the start of summer with an increase in daylight and sun hours, reaching 10 hours, and the temperature warms up to an average high of 28 °C (82 °F). Nights are quite pleasant with an average in the low double digits at 11 °C (51 °F), and the precipitation calms down to an average of 50 mm (1.96 in).
July weather
July peaks in terms of heat with the highest average high temperatures of the year at 31 °C (89 °F), making it the hottest month. It's a dry and sunny month too, with only around 11 of precipitation and a continuing average wind speed of 3.
August weather
The warmth lingers in August with daytime highs averaging 30 °C (86 °F), but the nights begin to hint at the approaching fall, averaging around 14 °C (56 °F). August tends to have a slightly lower amount of precipitation with 43 mm (1.68 in), and the generous sunshine hours of 10 hours illuminate the stunning Colorado landscape.
September weather
September in Boulder marks the beginning of the transition to autumn. Daytime highs remain pleasant at an average of 25 °C (77 °F), and night temperatures dip to a cooler average of 8 °C (47 °F). With precipitation at around 40 mm (1.58 in), the scenic landscape slowly turns gold and crimson.
October weather
With the arrival of October, Boulder fully embraces the autumnal chill. The average high temperature drops to 19 °C (66 °F) while nights can be brisk with an average low of 2 °C (36 °F). Expect to see precipitation on roughly 6 against the backdrop of the vibrant fall colors.
November weather
November sees a further decline in temperatures as winter approaches. Daytime averages settle at 12 °C (53 °F), while chilly nights average around -3 °C (26 °F). The wind remains consistent, and the amount of precipitation falls to 30 mm (1.19 in) over an estimated 7.
December weather
December in Boulder brings the full onset of winter again, with average daytime highs of 7 °C (45 °F) and nighttime lows frequently below freezing at approximately -7 °C (19 °F). The precipitation is slightly lower with about 7, and the wind speed eases a little to an average of 3.
FAQs
What should I wear for a day out in Boulder during January?
Layering up is key for a January day in Boulder. Consider thermal undergarments, a warm sweater or fleece, and a waterproof winter coat, as well as a hat, gloves, and sturdy boots suitable for potentially icy conditions.
Does it get very cold at night in Boulder during February?
February nights in Boulder do get rather cold with average temperatures of -6 °C (21 °F), so be sure to have warm bedding and heating arrangements for a cozy night's rest.
Does Boulder experience a significant amount of rain in March?
Boulder's march towards spring is marked by increasing precipitation, seeing rain on about 9, which can include rain or melting snow as the season transitions.
How warm is it during the day in Boulder in April?
During April in Boulder, the days grow significantly warmer with average high temperatures reaching 17 °C (62 °F), indicating a pleasant transition into the colorful spring season.
Is May considered the wettest month in Boulder?
Yes, May is typically the wettest month in Boulder, bringing with it a lush and verdant landscape. An average of 69 mm (2.72 in) of precipitation can make the month feel quite damp.
How hot does it typically get in Boulder during June?
Summer begins to make its presence known in Boulder during June with average high temperatures reaching a toasty 28 °C (82 °F). It's perfect for enjoying outdoor activities like biking, climbing, or lounging in the city's many parks.
Can I expect many rainy days in Boulder during the month of July?
July in Boulder typically means that rain becomes an infrequent visitor, occurring on just about 11, allowing for plenty of sun-soaked days perfect for outdoor fun.
As August is generally a warm month, how much rain should I expect in Boulder?
While August remains warm, it also brings slightly less rain compared to the wetter months, with average precipitation figures reaching around 43 mm (1.68 in) over the course of the month.
Does September in Boulder bring a significant change in weather?
September is a month of transformation in Boulder, with an appreciable shift in weather as the balmy days gradually give way to the crisp air of fall, signified by daytime temperatures averaging 25 °C (77 °F) and cooler evenings.
Is October a cold month in Boulder?
October in Boulder introduces cooler weather with the arrival of fall. It's not quite freezing yet, but temperatures average a cooler 19 °C (66 °F), so it's time to bring out those cozy sweaters and light jackets.
How cold does November get in Boulder?
In November, Boulder gears up for winter with daytime temperatures averaging 12 °C (53 °F) and nights that start to dip below freezing, averaging -3 °C (26 °F).
Is December in Boulder filled with many snow days?
While Boulder doesn't have a high number of snow days, December does see an average of 7 with precipitation, which can lead to a white blanket covering the city on some days.
We make the most from 40 years of historical weather data to predict the best weather conditions.
Deciding on where to go for a holiday is hard sometimes. Get inspired by the most popular destinations.
We aggregate data from combining multiple weather sources to ensure accuracy of the highest order.