May Weather in Palo Alto, United States

Last updated: February 24, 2025

As spring transitions to summer, Palo Alto experiences a delightful May climate characterized by warm temperatures and mild breezes. With maximums reaching 29°C (84°F), and an average of 15°C (59°F), outdoor activities abound under the California sun. Nights cool down to a refreshing minimum of 8°C (46°F), providing a comfortable retreat after sunny days. Although the month brings a modest precipitation total of 24 mm (0.9 in) over just 2 days, the humidity level rests at 71%, adding a touch of moisture to the air. This combination creates a vibrant atmosphere, ideal for enjoying the blossoming landscapes and abundant outdoor events.

May Temperature in Palo Alto

In May, Palo Alto begins to embrace the warmth of spring, showcasing a delightful temperature range that invites outdoor activities. With a minimum of 8°C (46°F) and a comfortable average of 15°C (59°F), the city starts to shake off the cooler months. The maximum temperature peaks at 29°C (84°F), signaling a taste of summer ahead. This trend reflects a consistent upward trajectory in temperatures as the season progresses, with days getting noticeably sunnier and longer. As May unfolds, residents and visitors alike capitalize on the milder weather, making it an ideal time for picnics, hikes, and enjoying the natural beauty that surrounds this vibrant locale.

May Weather in Palo Alto: Daily Temperature Highs, Lows, and Averages

The chart illustrates May temperature patterns in Palo Alto, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec525354565863636565625652
Data source: Temperature data for Palo Alto generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

May Precipitation in Palo Alto

In Palo Alto, May marks a significant transition into the dry season, with only 24 mm (0.9 in) of precipitation recorded over just 2 days. This sharp decline follows April's modest rainfall of 33 mm (1.3 in), highlighting a gradual descent in moisture as spring gives way to summer. The trend is clear: as the months progress towards the sun-soaked summer, precipitation drops dramatically from January's peak of 105 mm (4.1 in), and May’s figures are part of a broader seasonal pattern that sees rainfall plummet. With this limited rainfall, May sets the stage for the typically arid conditions of June and July, where not a single drop of rain is expected, allowing residents to embrace the vibrant, sunny days ahead.

May Precipitation Trends in Palo Alto

The chart displays monthly precipitation patterns in Palo Alto, with values for each month alongside May's data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how May's conditions compare to those of other months.
JanFebMarAprMayJunJulAugSepOctNovDec1051008633242012244788
Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.
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May Humidity in Palo Alto

In May, Palo Alto experiences a noticeable shift in humidity, dropping to 71% as spring transitions into summer. This reduction marks a continuation of the downward trend observed since April's 78%, indicating that the region is gradually becoming drier as it heads toward the warmer months. This decline in humidity opens the door to more comfortable outdoor conditions, setting the stage for pleasant outdoor activities. The trend of decreasing humidity persists into June, with levels reaching 64%, further highlighting the region's shift towards a more arid climate as summer settles in. Overall, May serves as a pivotal month that bridges the moistness of spring with the warmth and lower humidity typical of summer in Palo Alto.

May Average Humidity in Palo Alto

This chart illustrates the average monthly humidity levels in Palo Alto, with May's data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, allowing you to see how May's humidity levels compare to other months.
JanFebMarAprMayJunJulAugSepOctNovDec82%84%82%78%71%64%59%54%55%62%78%80%
Data source: Humidity data for May generated using information from the Copernicus Climate Change Service.

May UV Index in Palo Alto

As May rolls into Palo Alto, the UV Index reaches a striking 10, indicating a very high level of sun exposure. This elevates the risk of harm from unprotected sun exposure, with a burn time of just 15 minutes. Notably, May follows a pattern established in earlier months, where UV levels steadily climb from a moderate 3 in January to this peak in May. The trend highlights an increasing intensity of solar rays as spring transitions to summer, suggesting that residents should be particularly vigilant about sun protection during this time. With June on the horizon bringing even higher levels, it's essential to stay informed and proactive. For more insights into UV levels throughout the year, visit Palo Alto UV Index.

Maximum UV Index Levels in Palo Alto for May

The chart shows the monthly maximum UV Index (UVI) for Palo Alto in May, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues.
JanFebMarAprMayJunJulAugSepOctNovDec3589101111109743
Data source: Palo Alto May UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

May Sunshine in Palo Alto

In Palo Alto, the month of May shines brightly with an impressive 341 hours of sunshine, signaling the peak of spring's radiant embrace. As the year unfolds, a delightful trend emerges; daylight hours steadily increase, transitioning from 151 hours in January to a vibrant crescendo in May. Following this sunny month, June takes the lead with 355 hours, just slightly overshadowing May's glory, while the summer months maintain a generous allocation of sunshine. However, as the year wanes, a gradual decline occurs—September and beyond mirror the initial months, reminding us of the seasonal ebb and flow. This pattern not only highlights Palo Alto's abundant sunshine during late spring and summer but also underscores the charm of its changing seasons, inviting residents and visitors alike to bask in the warmth before the cooler months set in.

Monthly Sunshine Duration in Palo Alto: May Highlighted

The May sunshine duration represents the total number of hours Palo Alto experiences direct sunlight during the month of May, excluding cloudy or obstructed periods. This chart compares the sunshine duration of May with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec151h216h263h296h341h355h349h320h299h276h225h194h
Data source: Palo Alto May Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Palo Alto During May

In Palo Alto, May marks a turning point in the year's weather patterns, with a 62% chance of sunny days—the highest probability for sunshine since March. This increase from April’s 45% not only highlights the ascendancy of late spring but also places May in a favorable position compared to the surrounding months. As the region transitions from the cooler months, May stands out, enjoying a significant boost in sunlight, reflecting the arrival of warmer, more welcoming weather. This sunny trend continues into the summer, with June and August also showcasing high chances of clear skies, making May an ideal month for enjoying the outdoors in this vibrant Californian city.

Percentage of Sunny Days in May in Palo Alto

The chart illustrates the percentage of sunny days in Palo Alto throughout the year, with May highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often Palo Alto experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec39%55%58%45%62%57%48%61%58%53%46%35%
Data source: Palo Alto May chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Palo Alto in May

As spring transitions into summer, Palo Alto basks in an increasing abundance of daylight, reaching a delightful peak in May with 14 hours of sun. This month marks a significant transition from the shorter days of winter, which only offer 9 hours of daylight in January. As spring progresses, daylight steadily grows from 10 hours in February to 11 in March and 13 in April, creating a vibrant sense of renewal. The consistent 14-hour duration in both May and June sets the stage for long, warm days filled with opportunities for outdoor activities. Following this high point, the gradual decline begins in August as daylight slips back to 13 hours, eventually tapering off into the shorter days of fall and winter. This cyclical rhythm not only enhances the beauty of Palo Alto but also significantly influences its seasonal lifestyle.

Average Daylight Hours in Palo Alto for May

The chart illustrates the variation in daylight duration in Palo Alto throughout the year, with May highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 54m10h 49m11h 59m13h 11m14h 11m14h 41m14h 25m13h 31m12h 22m11h 10m10h 8m9h 36m
Data source: Palo Alto daylight hours, calculated by summing the hours between sunrise and sunset for each day.

May Winds in Palo Alto

In Palo Alto, the month of May brings a refreshing increase in wind speed, averaging 3.0 m/s (7 mph), marking a peak in the spring season. This uptick contrasts with the calmer months of winter, where speeds hover around 1.8 to 2.5 m/s. As spring unfolds, gentle breezes begin to sweep through the area, providing a pleasant backdrop for outdoor activities and gardening. In comparison, the preceding months of March and April, with consistent speeds of 2.6 m/s (6 mph), set the stage for May's vibrant gusts. However, as the summer heat approaches, one can expect June's winds to gradually decrease to 2.7 m/s, illustrating a trend of fluctuating breezes that accompany Palo Alto’s unique seasonal transitions.

Average May Wind Speed in Palo Alto

The chart displays monthly wind speed patterns in Palo Alto, with values for each month shown alongside May's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how May's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec2.22.52.62.63.0 m/s2.72.32.12.02.41.82.4
Data source: Palo Alto May wind data, generated using information from the Copernicus Climate Change Service.

How May Weather in Palo Alto Compares to Other Months

The weather in Palo Alto 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 Palo Alto and find detailed weather information for every month.

May and January present quite contrasting weather patterns. In May, temperatures range from a minimum of 8°C (46°F) to a maximum of 29°C (84°F), with an average of 15°C (59°F) and relatively low precipitation of 24 mm (0.9 in) occurring over just 2 days. The humidity in May is moderate at 71%, offering a pleasant spring climate. In contrast, January is much cooler, with temperatures ranging from a minimum of 2°C (36°F) to a maximum of 24°C (75°F), averaging 11°C (52°F). This month experiences significantly higher precipitation at 105 mm (4.1 in) over 7 days and a higher humidity level of 82%. For more specifics on January's weather, you can check Palo Alto weather in January.

When comparing the weather in May and February, significant differences emerge. May generally enjoys milder temperatures, with an average reaching 15°C (59°F), peaking at a comfortable 29°C (84°F), while February tends to be cooler, with an average of just 11°C (53°F) and a maximum of 24°C (76°F). Furthermore, February experiences substantially higher precipitation at 100 mm (3.9 in) over 8 days, compared to May's 24 mm (0.9 in) over just 2 days, indicating a much drier season in late spring. Additionally, humidity levels are slightly lower in May at 71%, compared to February's 84%, which contributes to a more pleasant atmosphere as spring approaches. For more detailed insights, you can check Palo Alto weather in February.

When comparing the weather in March and May, a distinct difference emerges. March has cooler temperatures, with a minimum of 4°C (40°F) and an average of 12°C (54°F), while May experiences warmer conditions, starting at a minimum of 8°C (46°F) and averaging 15°C (59°F). In terms of maximum temperatures, March peaks at 25°C (78°F), whereas May can reach up to 29°C (84°F). Precipitation is significantly higher in March, with 86 mm (3.4 in) over 11 days, compared to only 24 mm (0.9 in) on just 2 days in May. Additionally, humidity tends to be slightly higher in March at 82%, compared to 71% in May. For a detailed overview, check out Palo Alto weather in March.

May generally offers warmer temperatures compared to April, with average daily highs reaching up to 29°C (84°F) versus April's maximum of 30°C (87°F), although April's peak is slightly higher. The minimum temperatures in May start at 8°C (46°F), compared to April's 6°C (42°F), indicating a trend toward milder nights. Moreover, May experiences less precipitation, with only 24 mm (0.9 in) over 2 days, while April sees 33 mm (1.3 in) across 5 days, resulting in lower humidity in May at 71% compared to April's 78%. For more details, check Palo Alto weather in April.

In comparing the weather of May and June, a noticeable warming trend becomes evident. May experiences temperatures ranging from a minimum of 8°C (46°F) to a maximum of 29°C (84°F), with an average of 15°C (59°F). It also sees more rainfall, with 24 mm (0.9 in) over two days, and a humidity level of 71%. In contrast, June offers a warmer climate with minimum temperatures of 10°C (49°F) and maximums soaring to 35°C (96°F), averaging around 17°C (63°F). Notably, June boasts significantly lower precipitation at just 2 mm (0.1 in) over zero rainy days, and the humidity drops to 64%. For more detailed information, you can check out Palo Alto weather in June.

In May, the weather is characterized by a wider temperature range, with minimums dropping to 8°C (46°F) and average temperatures reaching about 15°C (59°F). The month sees some precipitation, averaging 24 mm (0.9 in) over two days, leading to a higher humidity level of 71%. In contrast, July brings slightly warmer conditions, with minimum temperatures at 11°C (53°F) and average temperatures around 17°C (63°F). Notably, July is much drier, with no recorded precipitation and a humidity level of just 58%. For more details about the weather in July, you can visit Palo Alto weather in July.

May and August present notably different weather patterns. In May, temperatures range from a minimum of 8°C (46°F) to a maximum of 29°C (84°F), with an average of 15°C (59°F). There's a modest amount of precipitation, totaling 24 mm (0.9 in) over two days, along with a higher humidity level of 71%. In contrast, August experiences warmer conditions, with temperatures ranging from a minimum of 12°C (54°F) to a scorching maximum of 35°C (96°F), and an average of 18°C (65°F). Notably, August is dry, receiving no precipitation and maintaining a lower humidity level of 54%. For more specific information about the climate in August, you can check Palo Alto weather in August.

May and September present differing weather characteristics. May typically experiences a wider temperature range with lows around 8°C (46°F) and highs reaching up to 29°C (84°F), while September starts with slightly warmer minimums at 10°C (50°F) and can peak dramatically at 39°C (103°F). May brings about 24 mm of precipitation over just two days, contributing to a higher humidity level of 71%. In contrast, September is notably drier, with only 2 mm of precipitation and no rainy days, resulting in a lower humidity of 55%. For more specific insights into September weather patterns, you can check out Palo Alto weather in September.

In comparing the weather between May and October, we observe that both months experience similar levels of precipitation, with May averaging 24 mm over 2 days and October also at 24 mm but over just 1 day. Temperatures in May range from a minimum of 8°C (46°F) to a maximum of 29°C (84°F), while in October, the minimum slightly drops to 7°C (45°F) but can reach up to a warmer maximum of 33°C (92°F). Additionally, humidity tends to be higher in May at 71%, compared to October's 62%. For further details, you can explore Palo Alto weather in October.

May and November exhibit distinct weather patterns, reflecting the transition from spring to late fall. In May, temperatures range from a minimum of 8°C (46°F) to a maximum of 29°C (84°F), with an average of 15°C (59°F). This month typically experiences lighter precipitation at 24 mm (0.9 in) over just 2 days and a humidity level of 71%.

In contrast, November sees cooler temperatures, with a minimum of 4°C (39°F) and a maximum of 27°C (80°F), averaging 13°C (56°F). The precipitation increases significantly to 47 mm (1.9 in) across about 5 days, contributing to a higher humidity of 78%. For a more detailed look at the weather specifics during November, you can visit Palo Alto weather in November.

May and December present distinctly different weather patterns. In May, temperatures range from a minimum of 8°C (46°F) to a maximum of 29°C (84°F), with an average of 15°C (59°F). The month typically sees low precipitation, averaging just 24 mm (0.9 in) over about 2 days, and experiences moderate humidity at 71%. In contrast, December is cooler, with temperatures ranging from 3°C (37°F) to 22°C (72°F) and an average of 11°C (52°F). This month receives significantly more rain, totaling 88 mm (3.5 in) over around 9 days, and has higher humidity levels at 80%. For more detailed information on December weather, you can visit Palo Alto weather in December.

Compare Palo Alto's Climate with Cities Worldwide

Conclusion: What to Expect From May Weather in Palo Alto

As spring transitions to summer, May in Palo Alto brings a delightful mix of mild temperatures and relatively low precipitation. Unlike the cooler months that precede it, May sees a significant rise in warmth, making outdoor activities more enjoyable and vibrant. However, despite the increase in warmth, the humidity remains moderate, ensuring that the weather is comfortable for both residents and visitors. With only a couple of days of rain, it's a wonderful time to explore the lush landscapes and engage in outdoor pursuits. For more insights on the overall weather patterns, check out Palo Alto Climate.