Last updated: February 24, 2025
In Mill Valley, United States, May brings a delightful mix of warmth and refreshing breezes, with average temperatures hovering around a pleasant 15°C (60°F). Residents can enjoy maximum highs reaching up to 30°C (86°F), perfect for outdoor activities, while cooler evenings dip to a comfortable 7°C (45°F). This month typically sees a modest precipitation amount of 20 mm (0.8 in) across just 2 days, allowing ample sunshine for exploration. With an average humidity of 83%, the air feels lush and invigorating, making May an ideal time to experience the beauty of Mill Valley.
In May, temperatures in Mill Valley, United States truly begin to reflect the vibrancy of spring, showcasing a delightful transition as the month unfolds. The minimum temperature hovers at 7°C (45°F), signaling a gentle warmth, while average highs can reach an inviting 30°C (86°F). This marks a notable increase from the cooler temps in earlier months, with May featuring an average of 15°C (60°F), making it one of the warmer times of the year. Such pleasant conditions invite outdoor exploration and gatherings, as the landscape blooms with life and the air fills with the anticipation of summer. As daylight lingers longer, residents and visitors alike find themselves drawn into the stunning natural beauty surrounding Mill Valley, enjoying the perfect mix of sunshine and refreshing cool breezes.
May in Mill Valley marks a significant shift in precipitation, with only 20 mm (0.8 in) of rain recorded over just 2 days. This decline follows a rainy April, which brought 35 mm (1.4 in) and sets the stage for the driest months ahead. Compared to earlier months, it's a stark contrast to January and February, which averaged over 110 mm, showcasing the region’s transition toward a drier summer. With June and July typically receiving minimal precipitation, May’s gentle showers hint at the end of the rainy season, making way for bright, sunny days ahead.
In Mill Valley, United States, May brings a humidity level of 83%, slightly above the previous month’s 79%. This uptick is part of a larger trend where humidity levels gradually decline from January’s peak of 85% down to a minimum of 79% in late autumn. However, as spring transforms into summer, the humidity begins to rise again, with June and July recording higher levels at 84% and 87% respectively. This cyclical pattern underscores the characteristic climate of the region, balancing between refreshing coastal breezes and the lush greenery that thrives in such moist conditions.
In May, Mill Valley experiences a dramatic increase in the UV Index, reaching a peak of 10, which categorizes it as very high. This significant rise, following a steadily climbing trend from earlier months, indicates that sun exposure warrants caution, with a burn time of just 15 minutes for fair-skinned individuals. As spring unfolds, the sun’s intensity becomes more pronounced, urging residents and visitors to take proactive measures for sun protection. This trend continues into June with an even higher reading of 11, marking the onset of extreme UV conditions. The shift from moderate exposure in January and February to dangerously high levels by May highlights the importance of staying informed and prepared. For more information about the UV Index and how to stay safe, visit Mill Valley UV Index.
UV Risk Categories
In Mill Valley, May heralds the peak of sunshine with an impressive 356 hours of sunlight, beautifully setting the stage for the vibrant outdoor activities that characterize this time of year. As spring unfolds, daylight hours steadily increase from January's modest 148 hours, culminating in May's sun-drenched afternoons. This upward trend continues into early summer, where June captures the sunlight for 378 hours, hinting at the warmth and energy that lie ahead. The gradual dip in hours as summer transitions to fall reveals a rhythm of nature, with August still basking in 348 hours, but gradually declining with the arrival of September. As the daylight hours wane, Mill Valley embraces the changing seasons, each month providing its unique charm under varying skies.
As spring transitions into summer in Mill Valley, the likelihood of sunny weather in May takes a noticeable leap, reaching 75%. This marks a significant increase from the 66% forecasted for April, reflecting a clear upward trend in sunshine as the year progresses. After a gradual rise from January’s 39% to April, May’s robust prospects suggest that the days are not only getting longer but also brighter. Following May, June witnesses a slight dip to 65%, yet the overall trajectory emphasizes a shift towards sunnier, more enjoyable days, making May an ideal time to embrace the outdoors in this charming Californian locale.
As spring transitions into summer, Mill Valley witnesses a delightful increase in daylight duration that culminates in May, with the hours of sunlight peaking at 14 hours. Beginning the year with a modest 9 hours in January, the days gradually grow longer, adding an hour each month until April. May not only maintains this generous daylight but sets the stage for the summer months of June and July, which also enjoy 14 hours of sunshine. As summer gives way to autumn, daylight begins to taper off, leading to a gradual descent back to 10 hours in November. This pattern highlights a rhythmic ebb and flow of daylight, underscoring the vibrant seasonal changes that characterize life in Mill Valley.
In May, Mill Valley experiences a notable increase in wind speed, averaging 4.8 m/s (11 mph), which is the highest for the year. This rise, following a steady progression from April's 4.1 m/s (9 mph), indicates that spring is giving way to the more dynamic summer months. The wind begins to ease slightly in June at 4.4 m/s (10 mph), but the peak in May stands out as a transitional moment when the gentle breezes of early spring start to awaken the more invigorating winds of summer. This trend highlights May's role as a bridge between the calm of spring and the more robust gusts characteristic of the warmer season ahead.
The weather in Mill Valley changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of May's weather with other months, highlighting differences in temperature, precipitation, and other key factors. Click on each section to discover seasonal trends in Mill Valley and find detailed weather information for every month.
May and January present contrasting weather patterns in terms of temperature and precipitation. In May, temperatures range from a minimum of 7°C (45°F) to a pleasant average of 15°C (60°F), with maximums reaching 30°C (86°F). Although May sees less precipitation, with only 20 mm (0.8 in) over 2 days, the humidity is relatively high at 83%. In comparison, January experiences cooler temperatures, with a minimum of 0°C (33°F) and an average of 10°C (51°F), peaking at 23°C (73°F). However, it is much wetter, receiving 111 mm (4.4 in) of rain over 8 days, resulting in a humidity level of 85%. For more detailed insights, visit Mill Valley weather in January.
May and February present distinctly different weather patterns. In May, temperatures range from a minimum of 7°C (45°F) to a maximum of 30°C (86°F), with an average of 15°C (60°F). The month is relatively dry, with only 20 mm (0.8 in) of precipitation occurring over 2 days and humidity sitting at 83%. In contrast, February has cooler temperatures with a minimum of 2°C (35°F) and a maximum of 23°C (73°F), averaging 11°C (52°F). It is significantly wetter, receiving 116 mm (4.6 in) of rain spread across 8 days, while humidity remains slightly lower at 82%. For more details on February weather, visit Mill Valley weather in February.
In comparing the weather between May and March, May generally presents warmer conditions, with average temperatures ranging from a minimum of 7°C (45°F) to a maximum of 30°C (86°F), compared to March, which has temperatures spanning from a minimum of 4°C (39°F) to a maximum of 24°C (75°F). Furthermore, May experiences significantly less precipitation, with only 20 mm (0.8 in) recorded over just 2 days, in contrast to March’s considerably wetter climate, which sees 80 mm (3.1 in) over 10 days. Humidity levels are slightly higher in May at 83%, compared to March's 82%. For a detailed look at March's weather patterns, you can refer to Mill Valley weather in March.
When comparing the weather in May to that of April, we can observe some noteworthy differences. May generally experiences slightly warmer temperatures, with minimums around 7°C (45°F) and a maximum reaching up to 30°C (86°F), compared to April's lower min of 4°C (40°F) and max of 28°C (83°F). Additionally, May sees less precipitation, totaling only 20 mm (0.8 in) over just 2 days, while April has more rainfall at 35 mm (1.4 in) spread over 5 days. Humidity levels are relatively similar, with May at 83% and April slightly lower at 79%. For a deeper dive into April's weather specifics, check out Mill Valley weather in April.
May and June showcase a transition in weather patterns, with June generally being warmer and drier. In May, temperatures range from a minimum of 7°C (45°F) to a maximum of 30°C (86°F), with an average of 15°C (60°F) and 20 mm of precipitation over 2 days. Conversely, June starts with a slightly higher minimum temperature of 10°C (51°F) and peaks at 32°C (90°F), yielding an average of 17°C (63°F). Notably, June experiences significantly less rainfall, with only 2 mm over no precipitation days, while humidity levels remain quite similar at 83% in May and 84% in June. For more detailed insights, you can check Mill Valley weather in June.
May and July present distinct weather patterns despite having similar maximum temperatures. In May, temperatures range from a minimum of 7°C (45°F) to a maximum of 30°C (86°F), with an average of 15°C (60°F). This month experiences slightly higher precipitation at 20 mm (0.8 in) over two days, contributing to a humidity level of 83%. In contrast, July shows a warmer range starting at a minimum of 11°C (52°F) and averaging 17°C (63°F), with maximum temperatures again reaching 30°C (87°F). However, July stands out for its dryness, recording only 2 mm (0.1 in) of rain over no rainy days, while the humidity increases slightly to 87%. For a closer look at July's weather specifics, check out Mill Valley weather in July.
May and August present contrasting weather patterns. In May, temperatures range from a minimum of 7°C (45°F) to a maximum of 30°C (86°F), with an average of 15°C (60°F). The month sees some precipitation, totaling 20 mm (0.8 in) over 2 days, and the humidity sits at 83%.
In contrast, August experiences milder temperatures with a minimum of 11°C (52°F) and a maximum of 32°C (90°F), while the average temperature rises to 18°C (64°F). Notably, August is much drier, receiving only 1 mm (0.1 in) of rain and no recorded rainy days, alongside slightly higher humidity at 87%. For a detailed look at what to expect, check out Mill Valley weather in August.
May and September offer distinct climates, reflecting the transition from spring to autumn. In May, temperatures range from a minimum of 7°C (45°F) to a maximum of 30°C (86°F), with an average of 15°C (60°F). The month sees some rainfall, with about 20 mm (0.8 in) recorded over 2 days, and humidity levels are relatively high at 83%. In contrast, September presents warmer conditions, with minimum temperatures of 9°C (49°F) and maximums reaching up to 36°C (98°F), averaging 18°C (65°F). Notably, September experiences much less rain, with only 2 mm (0.1 in) and no precipitation days, while humidity slightly increases to 86%. For more detailed insights, you can check Mill Valley weather in September.
In May, temperatures range from a cool 7°C (45°F) to a warm 30°C (86°F), with an average of 15°C (60°F) and relatively low precipitation of 20 mm (0.8 in) over just two days. The humidity is quite high at 83%, contributing to a generally tropical feel. In contrast, October sees slightly cooler temperatures, with a minimum of 6°C (44°F), an average of 16°C (62°F), and a maximum of 31°C (88°F). It experiences increased precipitation at 30 mm (1.2 in) over the same two days, but the humidity drops slightly to 80%. For more detailed information, check out Mill Valley weather in October.
May and November exhibit distinct weather characteristics, reflecting the transition from spring to late fall. In May, temperatures range from a comfortable 7°C (45°F) at night to a warm 30°C (86°F) during the day, with an average of 15°C (60°F). The month sees relatively low precipitation, with only 20 mm (0.8 in) and rain on just 2 days, contributing to an overall humidity of 83%. In contrast, November experiences cooler temperatures, with minimums of 3°C (37°F) and maximums reaching 25°C (77°F), averaging 13°C (55°F). The month is wetter, accumulating 48 mm (1.9 in) of rain over 5 days, resulting in a slightly lower humidity of 79%. For more detailed insights, you can check Mill Valley weather in November.
May typically experiences warmer temperatures compared to December, with average highs reaching up to 30°C (86°F) and only occasional precipitation of about 20 mm (0.8 in) over just 2 days. In contrast, December is cooler, with average temperatures peaking at 22°C (72°F) and significantly higher precipitation of 98 mm (3.9 in) spread over 9 days. The humidity remains relatively high in both months, with May at 83% and December slightly lower at 79%. For a more detailed look at December weather, you can visit Mill Valley weather in December.
May in Mill Valley is a delightful transition into warmer weather, characterized by pleasant temperatures that stand in contrast to the chill of earlier months. With an average around 15°C, days can peak at a warm 30°C, inviting residents and visitors alike to enjoy the great outdoors. Although light rain may grace the area on just a couple of days, the high humidity levels often lend a refreshing feel to the air. This blend of warmth and moisture makes May a unique experience compared to the cooler, wetter months preceding it. For more detailed insights into the area's climate, check out Mill Valley Climate.