May Weather in Philadelphia, United States

Last updated: February 24, 2025

May in Philadelphia offers a vibrant transition into warmer weather, with temperatures reaching a maximum of 32°C (90°F) and an average of 14°C (57°F). However, early spring chills can still linger, as evidenced by a minimum recorded temperature of -2°C (29°F). This month also sees 104 mm (4.1 in) of rain spread across 13 days, contributing to a humidity level of approximately 75%, making the air feel warm and balmy. As nature bursts into bloom, May encapsulates the charm of Philadelphia, welcoming residents and visitors alike with its mix of sunshine and refreshing showers.

May Temperature in Philadelphia

In May, Philadelphia experiences a delightful transition into warmer weather, with temperatures gradually rising compared to the preceding months. The minimum temperature reaches a brisk -2°C (29°F), while the average climbs to a pleasant 14°C (57°F), providing a stark contrast to the lingering chill of early spring. With maximum daytime temperatures soaring to a balmy 32°C (90°F), May marks the arrival of more consistent warmth, enticing locals and visitors alike to embrace outdoor activities. This month sets the stage for a full-fledged summer, showcasing a notable increase in temperatures as the city shakes off the winter chill and welcomes sunnier days ahead.

May Weather in Philadelphia: Daily Temperature Highs, Lows, and Averages

The chart illustrates May temperature patterns in Philadelphia, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec222432445765716962523728
Data source: Temperature data for Philadelphia 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 Philadelphia

In May, Philadelphia experiences a noteworthy transition with 104 mm (4.1 in) of precipitation over approximately 13 days, striking a balance between the wetter conditions of April and the summer months ahead. This slight decrease from April's heavier rainfall of 130 mm (5.1 in) highlights a tapering off as spring blooms into summer. Interestingly, the rainfall in May is on par with June, suggesting a consistent pattern in early summer precipitation. While January through April set the stage for the year with varied precipitation, it's May's mild yet steady rain that helps nurture the lush, vibrant landscapes before the hotter, more humid months roll in.

May Precipitation Trends in Philadelphia

The chart displays monthly precipitation patterns in Philadelphia, 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.
JanFebMarAprMayJunJulAugSepOctNovDec8684881301041041371067516111998
Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.
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May Humidity in Philadelphia

As spring transitions into summer, May brings a refreshing drop in humidity levels in Philadelphia, settling at around 75%. This decline marks a shift from the high humidity typical of the early year, where both January and February consistently hover at 93%. As the seasons progress, the humidity gradually decreases, reflecting the arrival of warmer and drier months. April showcases this trend with a slight reduction to 82%, paving the way for May's more comfortable atmosphere. Following May, the humidity continues its descent, reaching its lowest point in June at 68%. Overall, this pattern highlights Philadelphia’s movement towards more pleasant conditions, encouraging outdoor activities and enjoyment of the city’s vibrant springtime.

May Average Humidity in Philadelphia

This chart illustrates the average monthly humidity levels in Philadelphia, 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.
JanFebMarAprMayJunJulAugSepOctNovDec93%93%86%82%75%68%69%67%72%83%88%89%
Data source: Humidity data for May generated using information from the Copernicus Climate Change Service.

May UV Index in Philadelphia

As May approaches in Philadelphia, residents can expect a significant uptick in UV exposure, with the UV Index soaring to 9, categorized as very high. This marks a steep increase from the milder indices of earlier months, such as 2 in January and 4 in February. With just 15 minutes of sun exposure needed to risk sunburn, it's essential for sun enthusiasts to take precautions, as the intensity remains consistent through June and July. This trend highlights the critical need for sun safety during these warmer months. For more details on the UV Index patterns, visit Philadelphia UV Index.

Maximum UV Index Levels in Philadelphia for May

The chart shows the monthly maximum UV Index (UVI) for Philadelphia 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.
JanFebMarAprMayJunJulAugSepOctNovDec245899997532
Data source: Philadelphia 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 Philadelphia

May in Philadelphia ushers in a delightful surge of sunshine, with 273 hours of glorious light illuminating the city. This vibrant month marks a significant increase from the 225 hours in April, setting the stage for the summer months ahead. As daylight extends, May not only provides a warmth that awakens the blossoming scenery but also signals a transition, as June brings an even more robust 319 hours of sun. This upward trend showcases Philadelphia's gradual shift from the winter chill, offering residents and visitors a chance to bask in the beauty of early summer days. The increasing sunlight in May invites outdoor adventures and fosters a renewed energy as the city blossoms into the warmer months.

Monthly Sunshine Duration in Philadelphia: May Highlighted

The May sunshine duration represents the total number of hours Philadelphia 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.
JanFebMarAprMayJunJulAugSepOctNovDec107h145h223h225h273h319h339h326h281h194h149h117h
Data source: Philadelphia May Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Philadelphia During May

In Philadelphia, the promise of sunny weather begins to bloom as spring unfolds, with May showcasing a 43% chance of sunny days. Compared to earlier months, this figure reflects a notable increase from January's bleak 24% and even beats April's 36%. As the city transitions into the warmth of summer, the likelihood of sun remains relatively steady, dipping slightly in June to 39% and in July to 34%. This trend highlights May as a delightful month, where residents can relish in the outdoors as sunshine begins to dominate the weather, setting the tone for the vibrant summer ahead.

Percentage of Sunny Days in May in Philadelphia

The chart illustrates the percentage of sunny days in Philadelphia 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 Philadelphia experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec24%26%46%36%43%39%34%42%40%32%41%23%
Data source: Philadelphia May chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Philadelphia in May

As spring transitions into summer, May stands out in Philadelphia with an average daylight duration of 14 hours, marking a significant increase from the 11 hours in March and 13 hours in April. This month serves as a delightful prelude to the longest days of summer in June and July, which each boast 15 hours of daylight. The gradual lengthening of days not only heralds warmer weather but also encourages outdoor activities and community gatherings. As the year progresses, daylight begins to decline in August, signaling a shift toward the cozy ambiance of fall, but for now, May shines brightly, inviting residents to bask in its extended hours of sunshine.

Average Daylight Hours in Philadelphia for May

The chart illustrates the variation in daylight duration in Philadelphia throughout the year, with May highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 17m10h 28m11h 57m13h 29m14h 47m15h 25m15h 4m13h 55m12h 27m10h 56m9h 36m8h 54m
Data source: Philadelphia daylight hours, calculated by summing the hours between sunrise and sunset for each day.

May Winds in Philadelphia

In May, Philadelphia experiences a moderate average wind speed of 3.0 m/s (7 mph), maintaining the same calm breezes as seen in April. This gentle airflow is characteristic of the spring season, as the city transitions from the cooler months into warmer weather. Notably, January and July also record the lowest wind speeds at 2.6 m/s (6 mph), suggesting a seasonal pattern where winds tend to pick up slightly during the spring and fall months. As summer approaches in June, the wind speed increases slightly to 3.5 m/s (8 mph), hinting at more dynamic weather patterns ahead. Overall, May's conditions exemplify the city's mild spring ambiance, making it an ideal time for outdoor activities.

Average May Wind Speed in Philadelphia

The chart displays monthly wind speed patterns in Philadelphia, 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.
JanFebMarAprMayJunJulAugSepOctNovDec2.63.24.03.03.0 m/s3.52.62.63.23.03.33.7
Data source: Philadelphia May wind data, generated using information from the Copernicus Climate Change Service.

How May Weather in Philadelphia Compares to Other Months

The weather in Philadelphia 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 Philadelphia and find detailed weather information for every month.

When comparing the weather in May and January, the differences are striking. May boasts a much milder temperature range, with minimums around -2°C (29°F) and maximums reaching up to 32°C (90°F), while January experiences frigid temperatures that dip as low as -33°C (-27°F) and average around -6°C (22°F). Despite January’s lower precipitation levels of 86 mm (3.4 in) over 12 days, its high humidity at 93% adds to the cold's bite. In contrast, May sees more precipitation at 104 mm (4.1 in) spread over 13 days, but with a significantly higher average temperature of 14°C (57°F) and lower humidity at 75%. For a more detailed look at January conditions, check out Philadelphia weather in January.

May and February present dramatic contrasts in weather conditions. In February, temperatures can plummet to a minimum of -27°C (-16°F), with average highs around -4°C (25°F) and a significant humidity level of 93%. Precipitation is relatively low, with about 84 mm (3.3 in) over 12 days. In stark contrast, May features a more temperate climate, with temperatures ranging from a chilly minimum of -2°C (29°F) to a pleasant maximum of 32°C (90°F), and an average of 14°C (57°F). The humidity in May is also lower, at 75%, and it experiences slightly more rainfall at 104 mm (4.1 in) over 13 days. For a detailed look at February weather, you can visit Philadelphia weather in February.

Comparing the weather in May and March reveals a significant transition as spring unfolds into summer. In May, temperatures range from a chilly minimum of -2°C (29°F) to a warm maximum of 32°C (90°F), with an average temperature of 14°C (57°F). This month also experiences about 104 mm (4.1 in) of precipitation over 13 days, accompanied by a relative humidity of 75%. In contrast, March is much colder, with temperatures reaching a minimum of -22°C (-7°F) and a maximum of 21°C (70°F). The average temperature is around 0°C (32°F), and it has slightly less precipitation at 88 mm (3.5 in) over 12 days, along with a higher humidity of 86%. For a closer look at the conditions during this month, you can check out Philadelphia weather in March. Overall, May presents much milder and varied weather compared to the harsher cold of March.

Comparing the weather in April and May reveals notable differences. April experiences cooler temperatures, with a minimum of -7°C (19°F) and an average of 7°C (44°F), while May brings warmer conditions, featuring a minimum of -2°C (29°F) and an average of 14°C (57°F). Precipitation is slightly lower in May, totaling 104 mm (4.1 in) over 13 days, compared to April’s 130 mm (5.1 in) across 14 days. Additionally, humidity levels are higher in April at 82%, compared to 75% in May. For more details on April's weather, you can check Philadelphia weather in April.

May and June exhibit distinct weather patterns, with May displaying a broader temperature range, from a chilly minimum of -2°C (29°F) to a warm maximum of 32°C (90°F). The average temperature in May is around 14°C (57°F), coupled with relatively high humidity at 75%. In contrast, June starts off warmer with a minimum temperature of 3°C (38°F) and an average of 19°C (66°F), yet it shares the same maximum of 32°C (90°F) as May. Both months experience similar levels of precipitation, measuring 104 mm (4.1 in) over approximately 13 days, but June benefits from lower humidity at 68%. For more details on the specifics of June weather, you can explore Philadelphia weather in June.

In comparing the weather of May and July, we see distinct differences in temperature and overall climate. May experiences a broader temperature range, with minimums dipping as low as -2°C (29°F) and maximums reaching up to 32°C (90°F), resulting in an average temperature of 14°C (57°F). Precipitation is frequent as well, with about 104 mm (4.1 in) falling over 13 days and humidity hovering around 75%. In contrast, July boasts a milder climate with minimum temperatures of 9°C (49°F) and maximums peaking at 35°C (95°F), leading to a much warmer average of 22°C (72°F). July also sees slightly increased precipitation at 137 mm (5.4 in) over 14 days, but with lower humidity at 69%. For more detailed information about July's weather, you can check this link: Philadelphia weather in July.

May and August exhibit notable differences in weather patterns. In May, temperatures can vary dramatically, with a minimum of -2°C (29°F) and an average of 14°C (57°F), while reaching a maximum of 32°C (90°F). The month sees significant precipitation, with 104 mm (4.1 in) over 13 days, accompanied by a high humidity level of 75%. In contrast, August boasts a more stable temperature range, with a minimum of 7°C (44°F), an average of 21°C (70°F), and a maximum of 31°C (89°F). Precipitation is slightly higher at 106 mm (4.2 in) over 14 days, but humidity is lower at 67%, giving it a drier feel compared to May. For more details, check out Philadelphia weather in August.

May and September present interesting contrasts in weather patterns. In May, temperatures range from a chilly minimum of -2°C (29°F) to a warm maximum of 32°C (90°F), with an average of 14°C (57°F). The month experiences higher precipitation, totaling 104 mm (4.1 in) over 13 days, and the humidity sits at 75%. Conversely, September boasts slightly milder temperatures, with a minimum of 0°C (33°F) and an average of 17°C (62°F), while the maximum remains similar at 32°C (89°F). With lower precipitation at 75 mm (3.0 in) over just 9 days and a humidity level of 72%, September generally feels more comfortable. For more details on what to expect in September, check out Philadelphia weather in September.

May and October display notable differences in weather patterns. In May, temperatures range from a minimum of -2°C (29°F) to a maximum of 32°C (90°F), with an average of 14°C (57°F). The month experiences around 104 mm (4.1 inches) of precipitation over approximately 13 days, accompanied by a humidity level of 75%. In contrast, October features cooler temperatures, with minimums dipping to -3°C (26°F) and maximums reaching 26°C (80°F), averaging at 11°C (52°F). Precipitation increases to 160 mm (6.3 inches), occurring over about 14 days and a higher humidity of 83%. For more detailed insights, visit Philadelphia weather in October.

May and November present contrasting weather patterns, with May showcasing a much warmer climate. In May, temperatures range from a chilly minimum of -2°C (29°F) to a pleasant average of 14°C (57°F) and can reach up to 32°C (90°F). This month experiences around 104 mm (4.1 in) of precipitation over 13 days and a humidity level of 75%. In contrast, November brings much cooler conditions, with temperatures dipping to a minimum of -15°C (6°F) and an average of only 3°C (37°F), peaking at 22°C (73°F). Precipitation increases slightly to 119 mm (4.7 in) over 14 days, accompanied by higher humidity at 88%. For more detailed insights, you can check out Philadelphia weather in November.

May and December present stark contrasts in weather conditions. In May, the temperatures range from a chilly minimum of -2°C (29°F) to a warm maximum of 32°C (90°F), with an average of 14°C (57°F). This month typically sees 104 mm (4.1 in) of precipitation spread over 13 days, accompanied by a moderate humidity of 75%. In contrast, December is much colder, with temperatures plunging to a minimum of -27°C (-17°F) and rising only to a maximum of 16°C (61°F), resulting in an average temperature of -2°C (28°F). Precipitation levels are slightly lower at 98 mm (3.8 in), but the humidity rises to a brisk 89%. For a deeper dive into the specifics, you can refer to the Philadelphia weather in December.

Compare Philadelphia's Climate with Cities Worldwide

Conclusion: What to Expect From May Weather in Philadelphia

As spring transitions into summer, May in Philadelphia offers a delightful respite from the colder months, with temperatures climbing significantly higher than those seen in winter. The likelihood of rain increases, resulting in a more humid atmosphere that can feel quite sticky at times. However, the blend of warm days and cooler nights provides a refreshing contrast, making it one of the most comfortable months for outdoor activities. As you plan your spring adventures, keep in mind the unique weather patterns that May presents compared to the chill of earlier months. For a deeper dive into what to expect throughout the year, check out Philadelphia Climate.