Weather in May
Temperature
May's arrival coincides with a subtle temperature rise, moving from April's refreshing 13.2°C (55.8°F) to a comfortable 16.7°C (62.1°F). Throughout the month of May, Portsmouth witnesses an average temperature of 9.2°C (48.6°F).Rainfall
In Portsmouth, in May, during 6.5 rainfall days, 43mm (1.69") of precipitation is typically accumulated. Throughout the year, in Portsmouth, there are 103.4 rainfall days, and 699mm (27.52") of precipitation is accumulated.Sea temperature
In Portsmouth, in May, the average water temperature is 11.5°C (52.7°F).Note: Beware when you're in 11.5°C (52.7°F) waters; 13°C (55.4°F) is chilling and anything below 10°C (50°F) could cause breathing hindrance and a sudden cold shock, given your physical condition.
Daylight
In May, the average length of the day is 15h and 32min.On the first day of the month, sunrise is at 5:36 am and sunset at 8:25 pm. On the last day of May, sunrise is at 4:56 am and sunset at 9:07 pm BST.
Sunshine
In May, the average sunshine is 7.8h.UV index
May through August, with an average maximum UV index of 6, are months with the highest UV index in Portsmouth, United Kingdom. A UV Index of 6 to 7 symbolizes a high threat to health from exposure to the Sun's UV rays for the ordinary person.Note: An average maximum UV index of 6 in May leads to these recommendations:
Continue precautions and advocate sun safety advice. Deterrence of sunburn is indispensable. Stay in the shade and avoid direct Sun exposure from 10 a.m. to 4 p.m., a period when UV radiation is particularly strong, noting that parasols or canopies may not offer total sun protection. Limit sun-induced ocular harm with sunglasses that feature UVA and UVB filtration.
Frequently asked questions
What are the temperatures in Portsmouth in May?
How much does it rain in Portsmouth in May?
How cold is the water in May in Portsmouth?
What is the average length of the day in May in Portsmouth?
When are sunrise and sunset in May in Portsmouth?
How long on average sun shines in May in Portsmouth?
What are the months with the highest UV index in Portsmouth?
What is the UV index reading in May in Portsmouth?
Average temperature in May
Portsmouth, United Kingdom
- Average high temperature in May: 16.7°C
The warmest months (with the highest average high temperature) are July and August (21.4°C).
The months with the lowest average high temperature are January and February (8.2°C).
- Average low temperature in May: 9.2°C
The month with the highest average low temperature is August (14.3°C).
The coldest month (with the lowest average low temperature) is February (2.8°C).
Average rainfall in May
Portsmouth, United Kingdom
- Average rainfall in May: 43.4mm
The wettest month (with the highest rainfall) is October (86.2mm).
The driest month (with the least rainfall) is June (42mm).
Average rainfall days in May
Portsmouth, United Kingdom
- Average rainfall days in May: 6.5 days
The months with the highest number of rainy days are January and December (11.2 days).
The month with the least rainy days is July (5.4 days).
Average sea temperature in May
Portsmouth, United Kingdom
- Average sea temperature in May: 11.5°C
The best month for swimming (with the highest average sea temperature) is September (17.3°C).
The coldest month (with the lowest average sea temperature) is March (8.6°C).
Average daylight in May /
Average sunshine in May
Portsmouth, United Kingdom
- Average daylight in May: 15h and 3min
The month with the longest days is June (Average daylight: 16h and 24min).
The month with the shortest days is December (Average daylight: 8h and 0min).
- Average sunshine in May: 7h and 5min
The month with the most sunshine is July (Average sunshine: 8h and 24min).
The month with the least sunshine is December (Average sunshine: 2h and 0min).
Average UV index in May
Portsmouth, United Kingdom
- Average UV index in May: 6
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 1).
Portsmouth, United Kingdom
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