May Weather in Pittsburgh, United States

Last updated: February 24, 2025

In May, Pittsburgh experiences a dynamic climate characterized by a maximum temperature reaching 31°C (89°F) and an average of 17°C (63°F), making it a month of warm days and cool nights. However, temperatures can dip as low as -2°C (29°F), showcasing the transition to summer. This month is marked by significant rainfall, with an average of 150 mm (5.9 in) spread across 17 wet days, resulting in a humidity level of 81% that adds to the lush greenery of the region. Whether enjoying the vibrant spring blooms or navigating the occasional downpour, May in Pittsburgh presents a blend of warmth and refreshing moisture, a testament to the city’s unique charm.

May Temperature in Pittsburgh

In May, Pittsburgh begins to shed the remnants of winter, showcasing a delightful transition into spring. The temperatures, with a minimum of -2°C (29°F) and an average of 17°C (63°F), reveal a significant warmth compared to the preceding months. This month peaks at a pleasant 31°C (89°F), inviting locals and visitors alike to indulge in outdoor activities. As the city blossoms with vibrant flora, May marks a beautiful awakening, providing a stark contrast to the frigid temperatures of winter and setting the stage for the full warmth of summer ahead. The increasing average temperatures signal the shift towards more temperate conditions, making May an ideal time to explore Pittsburgh's parks and riversides.

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

The chart illustrates May temperature patterns in Pittsburgh, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec313541516270757367574236
Data source: Temperature data for Pittsburgh 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 Pittsburgh

May in Pittsburgh marks a significant transition into the wetter months, with precipitation levels reaching 150 mm (5.9 in) across 17 rainy days. This uptick represents an increase from April's 132 mm (5.2 in) and sets the stage for the even wetter days of June and July, which both average slightly more than May. The persistence of rain not only nurtures the vibrant spring blooms but also hints at a trend where the late spring months consistently usher in higher rainfall, laying the groundwork for lush greenery throughout the region. As daylight increases and temperatures rise, May’s precipitation not only enhances the beauty of Pittsburgh's landscape but also signals the gradual shift into the summer season, where rain remains a key player in the local climate narrative.

May Precipitation Trends in Pittsburgh

The chart displays monthly precipitation patterns in Pittsburgh, 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.
JanFebMarAprMayJunJulAugSepOctNovDec951261091321511551548912812894102
Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.
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May Humidity in Pittsburgh

As spring transitions into summer, May humidity in Pittsburgh begins to noticeably drop, with levels at around 81%. This slight decline reflects a trend as the city moves from the higher humidity common in the earlier months—hovering around 87% in April—and paves the way for a more comfortable early summer atmosphere. Interestingly, while June sees a modest uptick in humidity to 83%, it remains significantly lower than the winter months where humidity levels soar to 88%. Overall, May represents a refreshing shift, signaling the advent of warmer weather while still embracing the lingering moisture typical of Pittsburgh's climate. This variation in humidity not only impacts the air quality but also sets the stage for a vibrant summer season ahead.

May Average Humidity in Pittsburgh

This chart illustrates the average monthly humidity levels in Pittsburgh, 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.
JanFebMarAprMayJunJulAugSepOctNovDec89%88%87%87%81%83%82%76%77%82%89%86%
Data source: Humidity data for May generated using information from the Copernicus Climate Change Service.

May UV Index in Pittsburgh

As we transition into May in Pittsburgh, the UV Index reaches a notable 10, placing it in the very high exposure category. This signifies a dramatic increase from the earlier months of the year, as January’s moderate UV Index of 3 suggests a much lower risk of harm from sun exposure. April's 9 indicates a shift toward more intense sunlight, yet May intensifies that trend, with a burn time of just 15 minutes. This elevated risk continues into the summer months; June, July, and August maintain a stable UV Index of 10, which means outdoor enthusiasts should be particularly vigilant about sun protection during this peak period. To stay informed about UV exposure in the city, check out the detailed data at Pittsburgh UV Index.

Maximum UV Index Levels in Pittsburgh for May

The chart shows the monthly maximum UV Index (UVI) for Pittsburgh 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.
JanFebMarAprMayJunJulAugSepOctNovDec356910101098642
Data source: Pittsburgh 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 Pittsburgh

May in Pittsburgh shines brightly with 267 hours of sunshine, marking a delightful surge as spring transitions into summer. This month stands out as the tipping point of increasing daylight, following the steady rise from 236 hours in April. The progression clearly illustrates the shift from the dreariness of winter, where January sees only 104 hours, to the vibrant light of late spring. As the days lengthen, Pittsburghers can bask in increasingly warm and sunny weather, paving the way for even sunnier months ahead, peaking at 332 hours in July. The trend not only highlights May's role as a precursor to summer's glory but also emphasizes the city's ability to shake off the winter blues and embrace the blossoming vitality of the season.

Monthly Sunshine Duration in Pittsburgh: May Highlighted

The May sunshine duration represents the total number of hours Pittsburgh 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.
JanFebMarAprMayJunJulAugSepOctNovDec104h135h223h236h267h301h332h316h277h219h173h137h
Data source: Pittsburgh May Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Pittsburgh During May

In Pittsburgh, the likelihood of sunny weather begins to rise noticeably as spring progresses, with a 35% chance of sunshine in May. This reflects a slight uptick from April's 38%, suggesting that while May offers more opportunities for clear skies, it remains inconsistent compared to the summer months. As the seasons advance into June and July, the chance of sun elevates further, peaking at 44% in July. Overall, May serves as a transitional month, bridging the lower probabilities of early spring and the sunnier days of summer, making it an exciting time for outdoor activities, albeit with expectations of some cloudy spells.

Percentage of Sunny Days in May in Pittsburgh

The chart illustrates the percentage of sunny days in Pittsburgh 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 Pittsburgh experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec22%20%46%39%35%37%44%38%51%33%37%26%
Data source: Pittsburgh May chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Pittsburgh in May

As spring transitions into summer, May in Pittsburgh marks a delightful uptick in daylight, boasting 14 hours of sunlight—a notable increase from 13 hours in April. This gradual lengthening of days is part of a broader trend, where sunlight steadily increases from the shortest days of January at 9 hours to the longest days in June, which feature a remarkable 15 hours. This invigorating surge in daylight not only brightens the landscape but also enhances outdoor activities and local festivities, inviting Pittsburghers to savor the warmth and vibrancy of early summer. As the month progresses towards June, residents relish in the longer evenings, signaling a perfect time for gatherings in parks and gardens under the soft glow of twilight.

Average Daylight Hours in Pittsburgh for May

The chart illustrates the variation in daylight duration in Pittsburgh throughout the year, with May highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 38m10h 40m11h 58m13h 18m14h 26m15h14h 42m13h 41m12h 24m11h 4m9h 54m9h 19m
Data source: Pittsburgh daylight hours, calculated by summing the hours between sunrise and sunset for each day.

May Winds in Pittsburgh

As May unfolds in Pittsburgh, residents experience a gentle shift in the winds, with average speeds dipping to 2.6 m/s (6 mph), marking a notable decrease from the preceding months. This subtle softening trend follows April’s milder breezes of 3.2 m/s (7 mph) and hints at the seasonal transition as summer approaches. Unlike the brisk winds of spring, which steadily increased from the start of the year, May’s calming gusts invite a more leisurely pace. Interestingly, this pattern continues into June, where winds further decline to 2.5 m/s (6 mph), indicating a seasonal lull that tends to accompany the warmer months. The trend paints a picture of Pittsburgh's evolving climate, where each month carves out its own distinct rhythm in the city's atmospheric symphony.

Average May Wind Speed in Pittsburgh

The chart displays monthly wind speed patterns in Pittsburgh, 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.
JanFebMarAprMayJunJulAugSepOctNovDec3.03.23.53.22.6 m/s2.52.32.02.92.83.13.2
Data source: Pittsburgh May wind data, generated using information from the Copernicus Climate Change Service.

How May Weather in Pittsburgh Compares to Other Months

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

May and January present starkly contrasting weather conditions. In May, temperatures range from a chilly minimum of -2°C (29°F) to a warm maximum of 31°C (89°F), with an average of 17°C (63°F). The month sees about 150 mm (5.9 in) of precipitation over 17 days, accompanied by a humidity level of 81%. In contrast, January experiences much colder weather, with temperatures ranging from a frigid -22°C (-8°F) to a more moderate high of 21°C (70°F), averaging around -1°C (31°F). Precipitation is lower in January at about 95 mm (3.7 in) over 12 days, and the humidity is slightly higher at 88%. For a closer look at January conditions, you can visit Pittsburgh weather in January.

May and February present a striking contrast in weather conditions. May boasts milder temperatures, with an average of 17°C (63°F) compared to February's chilly 1°C (35°F). The maximum temperature in May can reach up to 31°C (89°F), while February sees a high of only 25°C (77°F). Despite these warmer averages, May experiences more rainfall, totaling 150 mm (5.9 in) over 17 days, compared to February's 125 mm (4.9 in) over 15 days. Additionally, humidity levels are relatively high in both months, with May averaging 81% and February at 88%. For more detailed insights into February's weather, you can check Pittsburgh weather in February.

In comparing the weather of March and May, the differences are striking. March experiences much colder temperatures, with a minimum of -17°C (1°F) and an average of only 5°C (42°F), while May sees more pleasant conditions, featuring a minimum of -2°C (29°F) and an average temperature of 17°C (63°F). May also boasts a wider temperature range, peaking at a maximum of 31°C (89°F), compared to March's maximum of 25°C (78°F). Additionally, May tends to be wetter, with 150 mm (5.9 in) of precipitation over 17 days, compared to March's 109 mm (4.3 in) over 13 days. Humidity levels are relatively high in both months, with March at 87% and May at 81%. For more detailed insights, you can check out Pittsburgh weather in March.

In comparing the weather of April and May, it is evident that May experiences warmer temperatures, with an average of 17°C (63°F) compared to April's 11°C (52°F). The maximum temperatures in May can reach up to 31°C (89°F), while April's peak is slightly lower at 29°C (84°F). Precipitation is fairly consistent between the two months, but May sees a slight increase with 150 mm (5.9 in) over 17 days, compared to April's 132 mm (5.2 in) over 16 days. Humidity levels are high in both months, although April holds a slightly higher average at 87% compared to May's 81%. For more details on the April weather patterns, visit Pittsburgh weather in April.

May and June present a distinct transition in weather patterns. In May, temperatures range from a chilly minimum of -2°C (29°F) to a warm maximum of 31°C (89°F), averaging around 17°C (63°F). The month sees significant precipitation of 150 mm (5.9 in) over 17 days, alongside a humidity level of 81%. In contrast, June offers a more temperate climate with minimum temperatures rising to 5°C (41°F) and maximums reaching 33°C (92°F), resulting in an average of 21°C (70°F). While rainfall slightly increases to 155 mm (6.1 in) over just 16 days, humidity also rises to 83%. For more detailed insights, check out Pittsburgh weather in June.

May and July present distinct contrasts in weather patterns, with May experiencing a wider temperature range from a chilly minimum of -2°C (29°F) to a warm maximum of 31°C (89°F), while averaging around 17°C (63°F). In contrast, July enjoys milder conditions, with temperatures ranging from a minimum of 12°C (53°F) to a maximum of 35°C (96°F) and averaging 24°C (75°F). Both months receive a comparable amount of precipitation, with May seeing 150 mm (5.9 in) over 17 days and July experiencing slightly more at 154 mm (6.1 in) over 15 days. Humidity levels remain relatively similar, averaging 81% in May and 82% in July, creating a generally humid environment throughout both months. For more detailed insights, check out Pittsburgh weather in July.

May and August present distinct weather contrasts. In May, temperatures range from a minimum of -2°C (29°F) to a maximum of 31°C (89°F), with an average of 17°C (63°F). The month also sees considerable precipitation, totaling 150 mm (5.9 in) over 17 days and a higher humidity level of 81%. In contrast, August is warmer and more stable, with temperatures ranging from a minimum of 11°C (52°F) to a maximum of 34°C (93°F), averaging 23°C (73°F). It features less rainfall, with only 89 mm (3.5 in) over 16 days and a slightly lower humidity of 76%. For more detailed insights, you can check out Pittsburgh weather in August.

May and September showcase distinct weather patterns, each with its unique characteristics. In May, temperatures range from a chilly -2°C (29°F) to a warm 31°C (89°F), averaging around 17°C (63°F). This month also sees considerable precipitation, accumulating about 150 mm (5.9 in) over approximately 17 days, accompanied by high humidity at 81%. In contrast, September experiences milder temperatures, with a minimum of 5°C (40°F) and a maximum of 34°C (93°F), while maintaining a comfortable average of 20°C (68°F). The precipitation in September is slightly lower at 128 mm (5.0 in) and falls over just 10 days, with humidity decreasing to 77%. For a detailed look at September's weather patterns, you can check Pittsburgh weather in September.

May and October both showcase a range of temperatures, with October exhibiting slightly cooler weather overall. In May, temperatures can dip to a minimum of -2°C (29°F) but often peak at a warm 31°C (89°F), averaging around 17°C (63°F). October, while still reaching a maximum of 31°C (89°F), features a slightly lower average temperature of 14°C (57°F) and a minimum of -1°C (31°F). Precipitation levels in May are higher, with 150 mm (5.9 in) over 17 days, compared to October's 128 mm (5.0 in) over 14 days. Humidity levels are closely matched, with May at 81% and October slightly higher at 82%. For more detailed information, you can visit Pittsburgh weather in October.

May and November exhibit distinct differences in weather patterns. In May, temperatures range from a chilly -2°C (29°F) at night to a warm average of 17°C (63°F), peaking at a pleasant 31°C (89°F) during the day. The month experiences considerable rainfall, totaling 150 mm (5.9 in) over 17 days, with humidity hovering around 81%. In contrast, November brings much colder temperatures, with lows plunging to -13°C (9°F) and an average temperature of just 5°C (42°F). The highs are milder, reaching 25°C (78°F) on warmer days. While November receives less precipitation at 94 mm (3.7 in) over 11 days, it is notably more humid, with humidity levels at 89%. For more detailed insights, check out Pittsburgh weather in November.

May and December present strikingly different weather patterns. In May, temperatures range from a chilly minimum of -2°C (29°F) to a warm maximum of 31°C (89°F), with an average of 17°C (63°F). The month features notable precipitation of 150 mm (5.9 in) spread over 17 days, and humidity levels sit at 81%. In contrast, December experiences a much colder climate, with temperatures dipping as low as -16°C (4°F) and peaking at 18°C (65°F), averaging around 2°C (36°F). Despite receiving less rainfall at 102 mm (4.0 in) over 12 days, December is marked by slightly higher humidity at 86%. For more details about December weather, check out Pittsburgh weather in December.

Compare Pittsburgh's Climate with Cities Worldwide

Conclusion: What to Expect From May Weather in Pittsburgh

As spring unfolds in Pittsburgh, May brings a delightful shift from the chill of earlier months. With temperatures rising and a noticeable increase in humidity, residents can finally shed the winter layers, reveling in warmer days mingled with occasional rain. This month stands out with its vibrant greenery and blooming flowers, yet rainfall is frequent, providing essential moisture for the lush landscapes. Compared to the colder months, May offers a refreshing atmosphere that hints at the summer heat ahead while still holding onto the crispness of spring. For those interested in understanding more about Pittsburgh's varied weather patterns throughout the year, visit Pittsburgh Climate.