May Weather in Portsmouth, United Kingdom

Last updated: March 17, 2025

In May, Portsmouth, United Kingdom experiences a delightful spring atmosphere characterized by average temperatures around 13°C (55°F), with highs reaching a pleasant 22°C (71°F). The month is marked by an occasional drizzle, as precipitation totals amount to 56 mm (2.2 in) over approximately 11 days, leading to a humidity level of 79%. This blend of mild temperatures and varied precipitation creates an invigorating backdrop for outdoor activities, showcasing the charm of Portsmouth during this vibrant transitional period.

May Temperature in Portsmouth

As May unfolds in Portsmouth, the arrival of warmer days signals a delightful transition from the chill of early spring. With minimum temperatures averaging around 5°C (41°F) and maximums climbing to a pleasant 22°C (71°F), the month showcases an average temperature of 13°C (55°F) that invites residents and visitors alike to enjoy the blooming landscape. This upward trend from April’s cooler 10°C (50°F) average highlights the much-anticipated warmth, making it a perfect time for outdoor activities. As the city shakes off its winter coat, May serves as a vibrant prelude to the balmy summer months ahead, offering plenty of sunshine and milder weather to explore Portsmouth’s coastal beauty.

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

The chart illustrates May temperature patterns in Portsmouth, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec444546495561646461565047
Data source: Temperature data for Portsmouth generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

May Precipitation in Portsmouth

In May, Portsmouth experiences a moderate precipitation level of 56 mm (2.2 in), spread across approximately 11 days. This marks a noticeable increase from the preceding month of April, which enjoyed significantly lighter rains of only 32 mm (1.3 in) over just 7 days. As spring transitions into early summer, May's rainfall can be somewhat unpredictable, contributing to the lush greenery that characterizes the landscape. Compared to the wetter months that follow, such as June and August, May serves as a bridge, offering ample moisture while still allowing for enjoyable days of clear skies, making it a delightful time for outdoor activities before the summer showers intensify.

May Precipitation Trends in Portsmouth

The chart displays monthly precipitation patterns in Portsmouth, 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.
JanFebMarAprMayJunJulAugSepOctNovDec68757032567358785711787118
Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

May Humidity in Portsmouth

As spring unfolds, May in Portsmouth, United Kingdom, ushers in a noticeable drop in humidity, settling at 79%. This marks a significant decrease compared to the higher levels of 85% in April. The transition into late spring showcases a general trend of decreasing humidity, as it paves the way for the more comfortable summer months ahead. Following May, humidity levels rise again in June to 80%, but they remain markedly lower than the winter months, which peak at an impressive 92% in November and December. This seasonal shift highlights Portsmouth's evolution from damp winter conditions to the milder, more pleasant atmosphere of late spring, inviting residents and visitors alike to relish the outdoor charm before summer's arrival.

May Average Humidity in Portsmouth

This chart illustrates the average monthly humidity levels in Portsmouth, 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.
JanFebMarAprMayJunJulAugSepOctNovDec91%89%86%85%79%81%71%76%82%91%92%92%
Data source: Humidity data for May generated using information from the Copernicus Climate Change Service.

May UV Index in Portsmouth

As spring transitions to summer in Portsmouth, May brings a notable increase in UV intensity, with the UV Index rising to a high level of 7. This shift signifies a marked change from the cooler months when UV exposure was low, highlighted by January and February's consistent Index of just 2. In May, the burn time decreases to only 25 minutes, urging residents and visitors alike to take precautions against sun exposure. This trend continues into June and July, with Index values peaking at 8 during the summer months, where burn times further shorten to 15 minutes. It's essential to stay informed, especially as the risk of skin damage increases significantly. For more details on fluctuating UV levels in Portsmouth, visit Portsmouth UV Index.

Maximum UV Index Levels in Portsmouth for May

The chart shows the monthly maximum UV Index (UVI) for Portsmouth 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.
JanFebMarAprMayJunJulAugSepOctNovDec224578876421
Data source: Portsmouth 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 Portsmouth

May shines brightly in Portsmouth, unveiling 410 hours of glorious sunshine that sets the tone for the summer ahead. This month stands out as a pivotal turning point, where daylight hours jump dramatically from April's 344 hours. As spring blossoms into its full glory, May not only introduces warmer temperatures but also lures residents and visitors outdoors to bask in longer, sunnier days. Following the exuberance of May, June and July continue to showcase impressive sunlight totals, peaking at 423 hours in July before gradually tapering off. This enchanting progression hints at the vibrant summers typical of the UK’s southern coast, making May a delightful prelude to the sun-soaked months that follow.

Monthly Sunshine Duration in Portsmouth: May Highlighted

The May sunshine duration represents the total number of hours Portsmouth 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.
JanFebMarAprMayJunJulAugSepOctNovDec105h146h222h344h410h407h423h386h320h252h159h118h
Data source: Portsmouth May Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Portsmouth During May

As spring gracefully unfolds into May, Portsmouth experiences a noticeable shift in sunny weather, with a chance of sunshine sitting at 41%. This improvement follows the brightening trend seen in April, where the likelihood of sunlight reaches an encouraging 58%, suggesting that the warmth of early summer is beckoning. However, compared to the sunniest month of March at 38%, May's chances reveal a dip, indicating a potential return to more variable weather patterns. This fluctuation emphasizes the unpredictability of the British climate, yet May remains a promising time for enjoying the outdoors amidst the blossoming scenery.

Percentage of Sunny Days in May in Portsmouth

The chart illustrates the percentage of sunny days in Portsmouth 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 Portsmouth experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec22%26%38%58%41%30%42%33%37%30%37%22%
Data source: Portsmouth May chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Portsmouth in May

As May unfolds in Portsmouth, the increase in daylight duration becomes particularly noticeable, with the days stretching out to an inviting 15 hours of light. This marks a significant leap from April's 13 hours, highlighting the arrival of spring in full swing. The trend continues upward as the city transitions into summer, peaking in June with a remarkable 16 hours of daylight. Following the vibrant summer months, daylight begins its gradual retreat, reminding residents of the cyclical nature of the seasons. By autumn, daylight decreases to 12 hours in September, then back to 10 hours in October, before settling at 8 hours in the colder months. The steady ebb and flow of daylight throughout the year paints a dynamic picture of life in Portsmouth, emphasizing the sun's pivotal role in shaping the mood and activities of the community.

Average Daylight Hours in Portsmouth for May

The chart illustrates the variation in daylight duration in Portsmouth throughout the year, with May highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec8h 31m10h 2m11h 55m13h 50m15h 31m16h 23m15h 55m14h 25m12h 34m10h 39m8h 56m8h 2m
Data source: Portsmouth daylight hours, calculated by summing the hours between sunrise and sunset for each day.

May Winds in Portsmouth

In May, Portsmouth experiences a gentle yet invigorating breeze with an average wind speed of 6.1 m/s (14 mph). This slight uptick from the calmer April days reflects the transition into late spring when the maritime climate begins to warm. Comparatively, January and October also mark higher winds of 6.4 m/s (14 mph), suggesting a pattern where early and late spring are lively, while summer months tend to calm down, with June and July seeing the lowest speeds, down to 4.0 m/s (9 mph). As the season progresses into the summer, the winds remain moderate, creating a perfect backdrop for serene coastal walks or outdoor activities. The consistent wind patterns not only contribute to the charm of Portsmouth but also herald the arrival of refreshing summer days, making May a delightful time to explore the seaside.

Average May Wind Speed in Portsmouth

The chart displays monthly wind speed patterns in Portsmouth, 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.
JanFebMarAprMayJunJulAugSepOctNovDec6.46.95.84.86.1 m/s4.04.65.34.86.25.36.4
Data source: Portsmouth May wind data, generated using information from the Copernicus Climate Change Service.

How May Weather in Portsmouth Compares to Other Months

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

May generally offers milder and more pleasant weather compared to January. With temperatures ranging from a minimum of 5°C (41°F) to a maximum of 22°C (71°F), May has a comfortable average temperature of 13°C (55°F). In contrast, January is colder, with temperatures fluctuating between 0°C (32°F) and 13°C (56°F) and an average of just 7°C (44°F).

Though both months experience precipitation on approximately 11 days, May receives less rainfall at 56 mm (2.2 in) compared to January's 68 mm (2.7 in). Additionally, January has a higher humidity level of 91%, while May's humidity sits at a relatively lower 79%. For more details on January's weather, you can check out Portsmouth weather in January.

May generally offers milder and more pleasant weather compared to February. With average temperatures ranging from a minimum of 5°C (41°F) to a maximum of 22°C (71°F), May sees more comfortable conditions, while February's temperatures hover lower, with a range of -3°C (28°F) to 13°C (55°F). Additionally, May experiences less precipitation, totaling 56 mm (2.2 in) over 11 days, in contrast to February's 75 mm (3.0 in) over 12 days. Humidity levels are also notably higher in February at 89%, compared to 79% in May. For more detailed information, visit Portsmouth weather in February.

In comparing May and March weather, there are notable differences in temperature and precipitation patterns. May boasts milder temperatures, with a minimum of 5°C (41°F) and a pleasant average of 13°C (55°F), compared to March, which experiences colder conditions with a minimum of -3°C (28°F) and an average of 8°C (47°F). Additionally, May experiences less precipitation, totaling 56 mm (2.2 in) over 11 days, whereas March has slightly higher precipitation levels of 70 mm (2.7 in) spread across 13 days. Humidity is also slightly lower in May at 79% compared to 86% in March, making May a more comfortable month overall. For more information, you can check Portsmouth weather in March.

May generally experiences milder temperatures compared to April, with minimums rising from 1°C (34°F) in April to 5°C (41°F) in May. The average temperature also increases to 13°C (55°F) in May, compared to April's average of 10°C (50°F), and the maximum temperature reaches a pleasant 22°C (71°F) in May, surpassing April’s maximum of 19°C (66°F). In terms of precipitation, May sees an increase to 56 mm (2.2 in) over 11 days, whereas April has a lower total of 32 mm (1.3 in) across 7 days. Humidity is slightly lower in May at 79%, compared to April’s 85%. For more detailed observations, check Portsmouth weather in April.

In comparing the weather of May and June, we see a notable increase in temperatures and a slight uptick in humidity. In May, temperatures range from a minimum of 5°C (41°F) to a maximum of 22°C (71°F), with an average of 13°C (55°F). The month experiences about 56 mm (2.2 in) of precipitation over 11 days, while maintaining a humidity level of 79%. In contrast, June brings warmer conditions, with temperatures starting at a minimum of 9°C (49°F) and reaching up to 25°C (76°F) for an average of 16°C (61°F). Although June sees a slight increase in precipitation to 73 mm (2.9 in), it accumulates over just 9 days, and humidity edges up to 80%. For a more detailed look at June conditions, check out this link: Portsmouth weather in June.

In May, temperatures range from a cool 5°C (41°F) at night to a pleasant 22°C (71°F) during the day, with an average of 13°C (55°F). The month sees about 56 mm (2.2 in) of precipitation over 11 days, contributing to a higher humidity level of 79%. In contrast, July offers warmer weather, with minimum temperatures of 12°C (53°F) and maximums reaching 25°C (78°F), resulting in an average temperature of 18°C (65°F). Precipitation increases slightly to 58 mm (2.3 in) over the same number of rainy days, but humidity is lower at 71%. For a detailed look at the weather conditions in July, check out Portsmouth weather in July.

The weather in May features cooler temperatures, with a minimum of 5°C (41°F) and an average of 13°C (55°F), while August enjoys warmer conditions, starting at 11°C (52°F) and averaging 18°C (64°F). In May, precipitation is notable with 56 mm (2.2 in) spread over 11 days, compared to August's 78 mm (3.1 in) over 12 days, suggesting that both months experience a fair amount of rain albeit slightly more in August. Additionally, humidity levels remain high in both months, with May at 79% and August slightly lower at 76%. For more specific details about the weather patterns in August, you can check Portsmouth weather in August.

May and September both experience mild temperatures, but there are notable differences in their climate. In May, temperatures range from a minimum of 5°C (41°F) to a maximum of 22°C (71°F), with an average of 13°C (55°F). This month sees around 56 mm (2.2 in) of rainfall over approximately 11 days, accompanied by a humidity level of 79%. In contrast, September offers slightly warmer conditions, with temperatures ranging from 8°C (47°F) to 24°C (76°F) and an average of 16°C (61°F). Rainfall is similar at 57 mm (2.2 in) across about 10 days, but humidity increases to 82%. For those interested in exploring more about September's weather, check out Portsmouth weather in September.

In May, temperatures typically range from a minimum of 5°C (41°F) to a maximum of 22°C (71°F), with an average of 13°C (55°F). The month sees about 56 mm (2.2 in) of precipitation spread over 11 days, and humidity levels average around 79%. In contrast, October experiences slightly cooler temperatures, with a minimum of 4°C (40°F) and a maximum of 20°C (68°F), while maintaining the same average of 13°C (56°F). However, October is notably wetter, accumulating 117 mm (4.6 in) of precipitation over 16 days and exhibiting higher humidity at 90%. For more detailed information, you can visit Portsmouth weather in October.

In May, temperatures in Portsmouth typically range from a minimum of 5°C (41°F) to a pleasant maximum of 22°C (71°F), with an average temperature of 13°C (55°F). This month experiences around 56 mm (2.2 in) of precipitation spread over approximately 11 days, resulting in a relatively comfortable humidity level of 79%. In contrast, November sees a drop in temperatures, with minimums of 1°C (33°F) and maximums reaching only 16°C (61°F), averaging at 10°C (50°F). Rain is more frequent in November, with a total precipitation of 87 mm (3.4 in) over about 15 days, contributing to a higher humidity level of 92%. For more detailed information on November's weather, visit Portsmouth weather in November.

May and December present a stark contrast in weather patterns. In May, temperatures range from a minimum of 5°C (41°F) to a pleasant average of 13°C (55°F), peaking at 22°C (71°F), accompanied by a moderate level of precipitation totaling 56 mm (2.2 in) over 11 days. The humidity in May sits at 79%, creating a comfortable atmosphere as spring unfolds.

In contrast, December experiences much colder temperatures, with a minimum of 0°C (33°F) and an average of only 8°C (47°F), reaching a maximum of 14°C (57°F). The month sees significantly higher precipitation at 118 mm (4.7 in) spread across 16 days, and humidity rises to 92%, contributing to a damp and chillier environment. For more details on what to expect, you can refer to this link: Portsmouth weather in December.

Compare Portsmouth's Climate with Cities Worldwide

Conclusion: What to Expect From May Weather in Portsmouth

As May unfolds in Portsmouth, the weather strikes a delightful balance between the lingering chill of early spring and the warmth that hints at summer's arrival. With average temperatures rising and humidity peaking, this month offers a refreshing change, though it also brings more frequent showers. While May sees a substantial jump in warmth compared to the cooler months, the unpredictability of rainfall becomes more prevalent, encouraging residents and visitors alike to embrace the beauty of the season. For those looking to explore what other months may offer, insights can be found at Portsmouth Climate.