May Weather in Boston, United Kingdom

Last updated: March 17, 2025

In Boston, United Kingdom, May experiences a delightful blend of warm and cool temperatures, with a maximum of 27°C (80°F), an average of 12°C (54°F), and dipping to a minimum of 1°C (35°F). The month is characterized by a moderate level of precipitation, totaling 65 mm (2.6 in) over approximately 12 days, contributing to the vibrant spring foliage. With humidity levels averaging 83%, residents and visitors alike can expect a refreshing atmosphere, making May a refreshing time to explore the charming streets and natural beauty of Boston.

May Temperature in Boston

As May arrives in Boston, United Kingdom, temperatures begin to warm noticeably, marking a shift from the chill of earlier months. With minimums averaging around 1°C (35°F) and maximums soaring to 27°C (80°F), this month presents not only the most significant temperature gains but also a delightful glimpse of summer on the horizon. The average temperature of 12°C (54°F) creates a comfortable ambiance, making it an ideal time for outdoor activities and enjoying the blossoming flowers. As spring reaches its zenith, May stands out as a transitional month, bridging the briskness of winter and the heat of summer, encouraging residents and visitors alike to embrace the lovely weather.

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

The chart illustrates May temperature patterns in Boston, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec414345485460646359534642
Data source: Temperature data for Boston 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 Boston

May in Boston, United Kingdom, brings a notable uptick in precipitation, with 65 mm (2.6 in) of rainfall recorded over 12 days. This increase marks a significant rise compared to the preceding months, particularly following April's drier stats of just 32 mm (1.3 in). While January to April showcases relatively moderate rainfall, May sets the stage for the wetter summer months ahead, as it transitions into June, which averages 74 mm (2.9 in). This pattern hints at a cloudier and more temperate climate, inviting bursts of vibrant greenery as the rainy season commences. The balance of rainfall days in May reinforces the trend that spring showers significantly contribute to Boston's lush landscapes, fostering a sense of renewal and vitality as the season unfolds.

May Precipitation Trends in Boston

The chart displays monthly precipitation patterns in Boston, 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.
JanFebMarAprMayJunJulAugSepOctNovDec435856326574698060745472
Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.
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May Humidity in Boston

As spring transitions into summer, May in Boston, United Kingdom, brings a slight dip in humidity, averaging 83% compared to the higher levels seen in the preceding months. This downward trend from January's 89% through April’s 85% signals a gradual easing of moisture in the air, providing a breath of fresh air before the drier conditions of summer. With June remaining steady at 83%, it seems that May marks the end of more humid spells, offering residents and visitors a comfortable respite as the days warm up. As summer approaches, the humidity will continue to decrease, making way for sunnier and drier days ahead.

May Average Humidity in Boston

This chart illustrates the average monthly humidity levels in Boston, 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%87%86%85%83%83%80%78%84%88%89%88%
Data source: Humidity data for May generated using information from the Copernicus Climate Change Service.

May UV Index in Boston

As May arrives in Boston, United Kingdom, the UV Index climbs to 7, signaling a high exposure category and a reduced burn time of just 25 minutes. This marks a noticeable increase compared to the earlier months; April’s index was only 5, while March reached 4. The trend indicates a steady progression towards higher UV levels as spring transitions into summer. By June, residents will face even more intense exposure with a very high index of 8. Therefore, it's essential to stay informed and take precautions now that sunnier days are upon us. For more details, visit Boston UV Index.

Maximum UV Index Levels in Boston for May

The chart shows the monthly maximum UV Index (UVI) for Boston 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.
JanFebMarAprMayJunJulAugSepOctNovDec124578875321
Data source: Boston 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 Boston

May is a standout month for sunshine in Boston, United Kingdom, with 378 hours of bright days, marking a peak that reflects the continual rise in daylight hours since the beginning of the year. This upward trend is particularly striking when compared to just 89 hours in January, showcasing how spring transitions into a vibrant summer. The sunny days of May are a delightful contrast to the gloom of winter, as the city basks in more than double the sunlight received just a few months prior. Following May, the sunshine slightly tapers off in June and July, yet it remains abundant compared to the earlier months. With its rich tapestry of sunlight, May truly embodies the joy of approaching summer, making it a cherished time for outdoor activities and vibrant community gatherings in Boston.

Monthly Sunshine Duration in Boston: May Highlighted

The May sunshine duration represents the total number of hours Boston 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.
JanFebMarAprMayJunJulAugSepOctNovDec89h144h195h321h378h352h374h359h286h228h139h103h
Data source: Boston May Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Boston During May

As May arrives in Boston, United Kingdom, the likelihood of enjoying sunny weather climbs to 31%, a notable increase from the chillier months. While April boasts a higher chance of sunshine at 44%, the transition into May still reflects a promising upward trend compared to the winter months, where sunshine chances dip to the low twenties. Following May, the probability of sun will decrease slightly into June at 29%, indicating that while spring begins to wane, there's still ample opportunity to bask in the beauty of early summer days. Overall, May serves as a delightful bridge between the brighter days of spring and the warmth of summer, inviting residents and visitors alike to savor the emerging sun.

Percentage of Sunny Days in May in Boston

The chart illustrates the percentage of sunny days in Boston 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 Boston experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec24%23%26%44%31%29%36%26%29%22%29%19%
Data source: Boston May chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Boston in May

In Boston, United Kingdom, the arrival of May brings a delightful increase in daylight, with 15 hours available for outdoor activities and exploration. This month follows the steady climb from 8 hours in January to 14 hours in April, illustrating the gradual transition from winter's darkness to the brightness of spring. As May unfolds, residents and visitors alike can revel in the extended daylight, which not only enhances the beauty of the blooming surroundings but also invites more outdoor gatherings and adventures. This trend of increasing daylight continues into June, peaking at 16 hours, before gently tapering off as the summer months give way to autumn. The sharp rise in daylight during this period serves as a reminder of the seasonal cycle, highlighting the vibrant energy that May brings to the community.

Average Daylight Hours in Boston for May

The chart illustrates the variation in daylight duration in Boston throughout the year, with May highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec8h 11m9h 51m11h 54m14h15h 50m16h 49m16h 17m14h 38m12h 36m10h 32m8h 39m7h 38m
Data source: Boston daylight hours, calculated by summing the hours between sunrise and sunset for each day.

May Winds in Boston

In May, Boston experiences a moderate wind speed of 4.4 m/s (10 mph), showcasing a slight uptick from the more sheltered April winds of 3.9 m/s (9 mph). This trend of fluctuating but generally mild breezes continues into the summer months, with a peak in October as winds intensify to 5.4 m/s (12 mph). Interestingly, the air currents slow down again from June to July, dipping to their annual lows at 3.5 m/s (8 mph). As the year progresses, August winds pick back up, hinting at a seasonal rhythm where spring and autumn winds tend to be stronger than the summer lull. Overall, May serves as a pleasant transition month, balancing tranquil spring days with the promise of the lively winds to come.

Average May Wind Speed in Boston

The chart displays monthly wind speed patterns in Boston, 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.
JanFebMarAprMayJunJulAugSepOctNovDec4.85.35.03.94.4 m/s3.83.54.33.95.44.94.8
Data source: Boston May wind data, generated using information from the Copernicus Climate Change Service.

How May Weather in Boston Compares to Other Months

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

May and January present starkly contrasting weather conditions. In May, temperatures range from a cool 1°C (35°F) at night to a pleasant average of 12°C (54°F) and can peak at 27°C (80°F) during the day, making it a time of warmth and blooming life. The month also sees about 65 mm (2.6 in) of precipitation spread over 12 days, paired with a humidity level of 83%.

In contrast, January is significantly colder, with temperatures dipping from a minimum of -4°C (26°F) to an average of 5°C (41°F) and peaking at a mild 15°C (59°F). This winter month experiences lower precipitation at 43 mm (1.7 in) over 8 days, although humidity is slightly higher at 89%. For more detailed insights, you can check out Boston weather in January.

In comparing the weather between May and February, it’s evident that May experiences milder temperatures with an average of 12°C (54°F) compared to February's cooler average of 6°C (43°F). May's maximum temperature can reach as high as 27°C (80°F), offering a much warmer environment, while February peaks at 17°C (63°F). Although May has slightly more precipitation at 65 mm (2.6 in) over 12 days, February follows closely with 58 mm (2.3 in) across 11 days. Humidity levels are also comparable, being at 83% in May and slightly higher at 87% in February. For a more detailed look at February's weather patterns, visit Boston weather in February.

In comparing the weather between March and May, it becomes clear that May enjoys milder temperatures and a more pleasant atmosphere. March starts off cooler, with average temperatures hovering around 7°C (45°F) and nighttime lows dipping to -5°C (24°F), while May sees a warmer average of 12°C (54°F), with maximum temperatures reaching up to 27°C (80°F). Although both months have similar precipitation days, May experiences slightly more rainfall at 65 mm (2.6 in) compared to March's 56 mm (2.2 in). Additionally, May's humidity of 83% is slightly lower than March's 86%, which can contribute to a more comfortable feel during this spring month. For a more detailed look at March weather, you may refer to Boston weather in March.

In comparing the weather between April and May, we see a noticeable warming trend. While April experiences a cooler average temperature of 9°C (48°F) with minimums dipping to -1°C (31°F), May sees a rise in average temperatures to 12°C (54°F) and a minimum of 1°C (35°F). Although the maximum temperature in April reaches 26°C (79°F), May's upper range is a bit higher at 27°C (80°F). Precipitation increases in May, with 65 mm (2.6 in) over 12 days compared to April's 32 mm (1.3 in) across 8 days, and humidity slightly decreases from 85% in April to 83% in May. For a more detailed look at April weather, you can visit Boston weather in April.

The weather in May features a temperature range from a chilly minimum of 1°C (35°F) to a pleasant maximum of 27°C (80°F), with an average of 12°C (54°F). With 65 mm (2.6 in) of precipitation spread over 12 days, May tends to be wet, but the humidity remains consistent at 83%. In contrast, June enjoys slightly warmer temperatures, with a minimum of 6°C (43°F), an average of 16°C (61°F), and a maximum of 30°C (86°F). Although June sees a bit more precipitation at 74 mm (2.9 in) over 11 days, the humidity remains the same at 83%. For more details on the June climate, check out Boston weather in June.

In May, the weather typically sees a broader range of temperatures, with a minimum of 1°C (35°F) and a maximum of 27°C (80°F), averaging around 12°C (54°F). This month also experiences relatively high humidity at 83%, alongside 65 mm (2.6 in) of precipitation spread over 12 days. In contrast, July offers warmer conditions with a minimum temperature of 8°C (47°F) and a much higher maximum of 33°C (91°F), leading to an average temperature of 18°C (64°F). Although July has slightly more precipitation at 69 mm (2.7 in), it falls over just 11 days, and the humidity is a touch lower at 79%. For more detailed insights on July weather, you can view Boston weather in July.

May and August exhibit distinct weather patterns, reflecting the transition from spring to summer. In May, temperatures range from a chilly 1°C (35°F) at night to a comfortable 27°C (80°F) during the day, with an average temperature of 12°C (54°F). The month experiences 65 mm (2.6 in) of precipitation across about 12 days, contributing to a notably high humidity of 83%. In contrast, August sees warmer conditions, with nighttime lows of 9°C (49°F) and daytime highs reaching up to 32°C (89°F). The average temperature increases to 17°C (64°F), and while precipitation slightly rises to 80 mm (3.1 in) over the same 12 days, humidity decreases to 78%. For a more detailed look at August weather, you can refer to Boston weather in August.

May and September exhibit similar yet distinct weather patterns. In May, temperatures range from a chilly 1°C (35°F) at night to a warm 27°C (80°F) during the day, with an average temperature of 12°C (54°F). The month sees about 65 mm (2.6 in) of rainfall over 12 days, accompanied by high humidity at 83%. In contrast, September experiences slightly milder evenings with a minimum temperature of 4°C (39°F) and daytime highs reaching 28°C (83°F), averaging 15°C (59°F). Rainfall is slightly less at 60 mm (2.4 in) over 10 days, with humidity remaining similar at 84%. For more details on September weather, visit Boston weather in September.

In comparing the weather of May and October, we find some similarities and differences. May typically sees a wider temperature range with minimums of 1°C (35°F) and maximums reaching 27°C (80°F), providing a more variable climate. Conversely, October has slightly warmer minimum and maximum temperatures, from 2°C (36°F) to 24°C (76°F), though it tends to feel cooler overall as the month progresses. Precipitation levels are similar, with May receiving 65 mm (2.6 in) over 12 days and October accumulating 74 mm (2.9 in) across 13 days, indicating a somewhat wetter autumn. Moreover, humidity is higher in October at 88% compared to 83% in May, which can create a more damp and overcast atmosphere. For more detailed insights, you can check out Boston weather in October.

May and November present contrasting weather experiences. In May, temperatures range from a chilly 1°C (35°F) at night to a warm 27°C (80°F) during the day, with an average of 12°C (54°F). The month sees approximately 65 mm (2.6 in) of precipitation over about 12 days, coupled with a humidity level of 83%, creating a pleasant spring atmosphere. In contrast, November is cooler, with temperatures dipping to a minimum of -2°C (29°F) and only reaching a maximum of 18°C (64°F), averaging 8°C (46°F). Precipitation in November is slightly less at 54 mm (2.1 in) over 10 days, but humidity is higher at 89%, contributing to a more overcast and damp feel. For a more detailed view of November weather, check out Boston weather in November.

May and December present contrasting weather patterns, with May enjoying milder temperatures and increasing warmth. In May, the minimum temperature is around 1°C (35°F), with an average of 12°C (54°F) reaching a maximum of 27°C (80°F). This month typically experiences about 65 mm (2.6 in) of precipitation over approximately 12 days, alongside a relatively high humidity of 83%. In contrast, December is cooler, with temperatures ranging from a minimum of -2°C (29°F) to a maximum of 15°C (59°F) and an average of just 6°C (43°F). The precipitation in December rises slightly to 72 mm (2.8 in) across 15 days, and humidity increases to 88%. For more information on December weather, check Boston weather in December.

Compare Boston's Climate with Cities Worldwide

Conclusion: What to Expect From May Weather in Boston

As May unfolds in Boston, the city transitions from the chill of early spring to warmer days, showcasing a delightful blend of mild temperatures and increased humidity. With maximums reaching up to 27°C (80°F), residents begin to enjoy the outdoors more fully; however, the average temperature still maintains a comfortable 12°C (54°F), marking a pleasant shift from the colder months. While rain is somewhat frequent, with 12 days of precipitation totaling around 65 mm (2.6 in), the overall atmosphere is invigorating, making it the ideal time for blooming landscapes and outdoor activities. For those curious about Boston's weather trends beyond May, explore more at Boston Climate.