Last updated: February 24, 2025
In Boulder, Colorado, the weather in July is marked by a delightful blend of warm temperatures and occasional precipitation. With maximums reaching 34°C (93°F) and an average temperature of 20°C (68°F), the days are typically sunny and inviting. However, early mornings can be cooler, dipping down to a minimum of 7°C (45°F). Over the month, the city experiences about 71 mm (2.8 in) of rain across 16 days, contributing to a relative humidity of 52%. Whether you're hiking the Rockies or enjoying local festivals, July offers a vibrant atmosphere filled with diverse weather patterns that keep the experience lively and refreshing.
In Boulder, July brings a welcome warmth as temperatures reach their peak for the year. With minimums averaging around 7°C (45°F) and maximums soaring to 34°C (93°F), residents and visitors alike can enjoy the outdoors under sunny skies. The average temperature settles at a comfortable 20°C (68°F), making it a prime time for hiking and outdoor activities. Compared to the chill of winter, July’s balmy conditions invite a stark contrast, showcasing the region's dramatic seasonal shifts. As the warmest month in Boulder, July not only sets the scene for summer adventures but also marks a vibrant peak in the area's climatic rhythm.
In July, Boulder experiences a noteworthy continuation of its wet season, with precipitation totaling 71 mm (2.8 in) over 16 days. This rainfall slightly decreases from June's 74 mm but remains consistent with the upward trend seen throughout the spring months, highlighted by May's substantial 134 mm. Despite an overall reduction in volume when compared to May and June, July's precipitation underscores a steady monsoon influence, providing crucial moisture during the peak of summer. This consistency in rainfall is essential for replenishing local ecosystems and supports the lush landscapes that define Boulder in the summer months. As the city transitions into August, the precipitation pattern continues to reflect the lingering summer showers, emphasizing the region's fluctuating climate dynamics.
As summer peaks in Boulder, July brings a significant drop in humidity to an average of 52%, making it one of the driest months of the year. This decline continues a downward trend that began in January with a notably high humidity of 88%. From the coldest winter months, where moisture is abundant, humidity steadily decreases, culminating in this refreshing mid-summer low, before slightly rising again in August. The shift not only marks a transition from the cooler, wetter months to the warmth of summer but also enhances the region's crisp, clear air, perfect for outdoor activities and enjoying the stunning Rocky Mountain views.
In July, Boulder experiences its peak UV Index, maintaining an intense 12, which falls into the extreme exposure category. This means that the potential for skin damage is significantly high, with a quick burn time of just 10 minutes. This trend of escalating UV exposure began in the spring, with values skyrocketing from a moderate 4 in January to the extreme levels we see in summer. Notably, the UV Index remains consistently high through July, mirroring June’s readings, before gradually declining in August. As outdoor activities peak during this sunny month, it's crucial for residents and visitors alike to take proper sun safety precautions. For more detailed insights, check out the full Boulder UV Index.
UV Risk Categories
July in Boulder, United States, basks in an impressive 378 hours of sunshine, marking it as one of the sunniest months of the year. This peak follows a steady increase in sunlight from the winter months, where January starts with just 185 hours, gradually climbing to 304 hours by April. As summer approaches, the sunshine hours soar, reaching 374 in June before hitting their zenith in July. After this dazzling month, August still enjoys a generous 351 hours, illustrating the consistent warmth and brightness that defines this vibrant season. It's clear that sunshine plays a pivotal role in Boulder’s charm, with each month building towards this brilliant climax in July, inviting residents and visitors alike to embrace the outdoors and soak in the sun.
July in Boulder, United States, welcomes a 59% chance of sunny weather, marking it as one of the sunniest months of the year. As the summer unfolds, the likelihood of clear skies gradually increases, building from a modest 56% in January to an impressive 69% by September. This upward trend highlights July as a pivotal point in the sunny season, nestled between the slightly cooler June and the sun-drenched August, which boasts a 65% chance of sunshine. With the warmth of summer in full swing, July stands out as a prime time for outdoor activities, making the most of the vibrant, sunny days.
In Boulder, Colorado, July shines brightly as one of the peak months for daylight duration, boasting an impressive 14 hours of sunlight. This extended daylight follows a gradual increase from January's 9 hours, as the days lengthen through the spring and early summer months. After reaching a zenith in July, the daylight begins to taper off slightly in August, suggesting a transition toward fall as the daylight decreases to 13 hours. This fluctuation in light not only marks the changing seasons but also invites residents and visitors alike to enjoy the vibrant outdoor activities that Boulder has to offer during these sun-drenched days.
In July, Boulder experiences one of its calmer months, with an average wind speed of 2.1 m/s (5 mph). This gentle breeze is consistent with the trending decrease observed since March, where wind speeds peaked at 2.5 m/s (6 mph). As the summer heats up, the winds tend to mellow, creating a serene atmosphere perfect for outdoor activities. Interestingly, as the year progresses, winds in Boulder tend to pick up again in the later months, particularly in November and December, where they reach speeds of 2.9 m/s (6 mph) and 3.0 m/s (7 mph), respectively. This annual pattern hints at the region's unique climatic character, balancing tranquility and refreshing gusts throughout the year.
The weather in Boulder changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of July's weather with other months, highlighting differences in temperature, precipitation, and other key factors. Click on each section to discover seasonal trends in Boulder and find detailed weather information for every month.
In July, temperatures range from a mild 7°C (45°F) at night to a warm 34°C (93°F) during the day, with an average of 20°C (68°F). Despite experiencing 16 days of precipitation totaling 71 mm (2.8 in), the humidity remains at a comfortable 52%. In stark contrast, January brings frigid temperatures, with lows plunging to -24°C (-12°F) and an average temperature of -3°C (26°F). The maximum temperature is a mere 15°C (59°F), and precipitation is significantly lower at 25 mm (1.0 in) over just 5 days, coupled with a much higher humidity level of 88%. This stark contrast highlights the seasonal extremes in Boulder, making each month distinctly unique. For more details, check out the Boulder weather in January.
July and February present stark contrasts in weather conditions. In July, temperatures range from a mild 7°C (45°F) at night to a hot 34°C (93°F) during the day, with an average of 20°C (68°F). Although there are 16 days of precipitation, the total rainfall is relatively moderate at 71 mm (2.8 in), and humidity sits at a comfortable 52%. In contrast, February experiences harsh cold, with temperatures plummeting as low as -26°C (-14°F) and averaging -4°C (26°F), even reaching a maximum of 20°C (69°F) on warmer days. The month sees less precipitation, totaling 36 mm (1.4 in) over just 9 rainy days, but humidity is significantly higher at 87%. This stark difference highlights the challenges of winter months compared to the summer warmth. For more insights on February weather, check out Boulder weather in February.
When comparing the weather in July and March, it becomes clear that these months exhibit stark contrasts. July boasts much warmer temperatures, with an average of 20°C (68°F) and a maximum reaching up to 34°C (93°F), while March struggles with much colder conditions, averaging just 2°C (35°F) and dipping as low as -21°C (-5°F). In terms of humidity, July enjoys a relatively comfortable 52%, whereas March experiences a much higher humidity level at 81%, contributing to a chillier feel. Additionally, both months see consistent precipitation, but July records slightly more rain (71 mm over 16 days) compared to March’s 62 mm over 11 days. For a detailed perspective on the weather in March specifically, you can visit Boulder weather in March.
In comparing the weather conditions of July and April, one can see significant differences. July typically boasts a milder temperature range with a minimum of 7°C (45°F), an average of 20°C (68°F), and a maximum of 34°C (93°F). In contrast, April experiences cooler temperatures, ranging from a minimum of -17°C (2°F) to a maximum of 24°C (75°F), with an average of 5°C (42°F). While both months have comparable precipitation levels—71 mm (2.8 in) in July and 68 mm (2.7 in) in April—July has more rainy days, totaling 16 compared to April's 12 days. Additionally, April's humidity at 76% surpasses July’s average of 52%, contributing to a different overall feel in the air. For more detailed insights into April's weather, you can check Boulder weather in April.
When comparing the weather of July and May, it’s clear that July experiences much warmer temperatures overall, with an average of 20°C (68°F) compared to May's cooler average of 10°C (50°F). The maximum temperature in July can reach a sweltering 34°C (93°F), while May peaks at a milder 27°C (81°F). Interestingly, both months share the same number of precipitation days, totaling 16, but May sees a significantly higher amount of rainfall at 134 mm (5.3 in) compared to July's 71 mm (2.8 in). Additionally, May tends to have higher humidity levels at 66%, compared to July's 52%. For more details on weather specifics, you can check Boulder weather in May.
In comparing the weather of June and July, both months showcase a wide temperature range with maximums reaching up to 34°C (93°F). However, July generally has a higher average temperature of 20°C (68°F) compared to June's average of 17°C (63°F). Notably, July experiences slightly less precipitation, with 71 mm (2.8 inches) over 16 days, compared to June's 74 mm (2.9 inches) over 14 days. Additionally, June tends to be more humid, with a humidity level of 58%, while July's humidity is recorded at 52%. For a closer look at the weather specifics in June, you can visit Boulder weather in June.
In comparing the weather between July and August, both months experience mild minimum temperatures, starting at around 7°C (45°F). July tends to be slightly warmer on average, with a mean temperature of 20°C (68°F) compared to August's average of 19°C (67°F). The maximum temperatures also reflect a similar trend, peaking at 34°C (93°F) in July and slightly lower at 33°C (91°F) in August. Precipitation is relatively close, with July receiving 71 mm (2.8 in) over 16 days and August slightly less at 67 mm (2.7 in) over 13 days. Humidity increases a bit in August, rising to 56% from July's 52%. For more detailed insights, you can check out Boulder weather in August.
In July, the weather typically features a wide temperature range, with minimums around 7°C (45°F) and maximums reaching up to 34°C (93°F). This month also experiences a fair amount of precipitation, averaging 71 mm (2.8 in) over 16 days, and humidity levels at 52%. In contrast, September sees cooler temperatures with minimums dropping to -4°C (25°F) and averages around 16°C (61°F), while the highs remain similar at 33°C (92°F). Precipitation decreases significantly to 42 mm (1.6 in) over just 8 days, and humidity rises to 65%. For more insights, check out Boulder weather in September.
July and October present strikingly different weather patterns. In July, temperatures range from a pleasant minimum of 7°C (45°F) to a warm maximum of 34°C (93°F), with an average of 20°C (68°F). The month is relatively humid at 52%, accompanied by 71 mm (2.8 in) of rain over 16 days. Conversely, October’s temperatures are notably cooler, with a minimum of -20°C (-5°F) and a maximum of 26°C (79°F), averaging just 7°C (45°F). Despite experiencing only 48 mm (1.9 in) of precipitation over just 7 days, October's humidity rises to 76%, indicating a shift to a more damp and crisp atmosphere. For a detailed look at what to expect, check out Boulder weather in October.
In July, the weather is characterized by warm temperatures, with an average of 20°C (68°F) and highs reaching up to 34°C (93°F), accompanied by moderate humidity at 52%. Rainfall is relatively frequent, with precipitation occurring on 16 days and totaling 71 mm (2.8 in). In contrast, November brings a dramatic shift, as temperatures drop significantly, with an average of just 2°C (36°F) and lows plummeting to -16°C (3°F). The month is much drier, with only 30 mm (1.2 in) of precipitation over 6 days, but humidity levels rise to 82%, adding a chill to the already brisk atmosphere. For a detailed look at the weather conditions in November, check out Boulder weather in November.
July and December present stark contrasts in weather. In July, temperatures range from a minimum of 7°C (45°F) to a maximum of 34°C (93°F), with an average of 20°C (68°F) and experiencing 71 mm (2.8 in) of precipitation over 16 days. The humidity sits at a moderate 52%, creating warm and often sunny conditions perfect for outdoor activities.
In contrast, December is much colder, with temperatures ranging from a chilling -19°C (-1°F) to a milder 19°C (67°F), averaging -2°C (29°F). The month sees significantly less precipitation, only 19 mm (0.8 in) across just 4 days, and higher humidity at 89%, contributing to a crisp and often frosty atmosphere. For more detailed information, check out Boulder weather in December.
July in Boulder showcases a vibrant shift in weather, marked by warm days and cooler nights that set it apart from other months. With maximum temperatures peaking around 34°C (93°F), the month invites both residents and visitors to enjoy outdoor activities under abundant sunlight. However, the frequent showers contribute to the overall preparation needed, as 16 days of precipitation remind us that summer storms can be unpredictable. Coupled with a humidity level of 52%, July's climate offers a unique balance of warmth and moisture, creating an invigorating atmosphere for exploration. For a deeper dive into Boulder’s climate trends, visit Boulder Climate.