Contents
- Weather in May
- Frequently asked questions
- Average temperature in May
- Average pressure in May
- Average wind speed in May
- Average humidity in May
- Average rainfall in May
- Average rainfall days in May
- Average snowfall in May
- Average snowfall days in May
- Average sea temperature in May
- Average daylight in May
- Average sunshine in May
- Average sunshine days in May
- Average UV index in May
- Average cloud cover in May
- Average visibility in May
Weather in May
Temperature
May's arrival brings a temperature shift, moving from a fresh 51.1°F (10.6°C) in April to a refreshing 61°F (16.1°C). The average temperature in Portsmouth drops to a chilly 48°F (8.9°C) during the night in the month of May.Humidity
The average relative humidity in May is 78%.Rainfall
In May, the rain falls for 14.8 days. Throughout May, 1.97" (50mm) of precipitation is accumulated. Throughout the year, there are 144.2 rainfall days, and 27.48" (698mm) of precipitation is accumulated.Snowfall
In Portsmouth, snow does not fall in May through September.Ocean temperature
In Portsmouth, the average seawater temperature in May is 47.3°F (8.5°C).Note: Dipping into 47.3°F (8.5°C) below 50°F (10°C) is possible with the right protection; absent that, anticipate cold shock and hampered breathing. Swimming momentarily at 55.4°F (13°C) can be jarring.
Daylight
In Portsmouth, New Hampshire, the average length of the day in May is 14h and 41min.On the first day of the month, sunrise is at 5:35 am and sunset at 7:44 pm. On the last day of May, sunrise is at 5:06 am and sunset at 8:15 pm EDT.
Sunshine
In May, the average sunshine is 8.5h.UV index
In Portsmouth, the average daily maximum UV index in May is 5. A UV Index of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for the average person.Note: A daily maximum UV index of 5 in May translates into the following instructions:
Proceed with care. Light skin individuals may be exposed to burns in fewer than 30 minutes. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average May temperature?
What is the average humidity in May?
How many days does it rain in May?
When it does not snow?
Does it snow in Portsmouth in May?
How cold is the water in May?
What is the average length of the day in May?
When are sunrise and sunset in May?
How long on average sun shines in May?
What is the UV index intensity in May?
Average temperature in May
Portsmouth, NH
- Average high temperature in May: 61°F
The warmest month (with the highest average high temperature) is July (76.3°F).
The month with the lowest average high temperature is January (31.8°F).
- Average low temperature in May: 48°F
The month with the highest average low temperature is July (62.6°F).
The coldest month (with the lowest average low temperature) is January (21.2°F).
Average pressure in May
Portsmouth, NH
- Average pressure in May: 30"Hg
The month with the highest atmospheric pressure is November (30.06"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in May
Portsmouth, NH
- Average wind speed in May: 8mph
The windiest month (with the highest average wind speed) is January (11.7mph).
The calmest month (with the lowest average wind speed) is July (6.6mph).
Average humidity in May
Portsmouth, NH
- Average humidity in May: 78%
The month with the highest relative humidity is June (80%).
The months with the lowest relative humidity are April and November (75%).
Average rainfall in May
Portsmouth, NH
- Average rainfall in May: 1.97"
The wettest month (with the highest rainfall) is October (2.83").
The driest month (with the least rainfall) is September (1.54").
Average rainfall days in May
Portsmouth, NH
- Average rainfall days in May: 14.8 days
The month with the highest number of rainy days is June (15 days).
The month with the least rainy days is January (7.5 days).
Average snowfall in May
Portsmouth, NH
- Average snowfall in May: 0"
The month with the highest snowfall is January (4.02").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in May
Portsmouth, NH
- Average snowfall days in May: 0 days
The month with the highest number of snowfall days is January (8.8 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average sea temperature in May
Portsmouth, NH
- Average sea temperature in May: 47.3°F
The best month for swimming (with the highest average sea temperature) is August (65.6°F).
The coldest month (with the lowest average sea temperature) is March (38.5°F).
Average daylight in May /
Average sunshine in May
Portsmouth, NH
- Average daylight in May: 14h and 4min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in May: 8h and 3min
The month with the most sunshine is August (Average sunshine: 10h and 36min).
The months with the least sunshine are February and December (Average sunshine: 4h and 48min).
Average sunshine days in May
Portsmouth, NH
- Average sunshine days in May: 14.8 days
The month with the most sunshine days is September (16.8 days).
The month with the least sunshine days is April (13.2 days).
Average UV index in May
Portsmouth, NH
- Average UV index in May: 5
The months with the highest UV index are July and August (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in May
Portsmouth, NH
- Average cloud cover in May: 45
The month with the most cloud cover is March (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility in May
Portsmouth, NH
- Average visibility in May: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Portsmouth, New Hampshire, USA
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