Weathermondo.com
United StatesThe weather in May in Portsmouth
It's pleasantly warm in May in Portsmouth with an average temperature of 20°C. Temperatures this month range from a low of 14°C to a high of 25°C. At night, you can expect temperatures between 5°C and 13°C.
Looking for great weather? May is a good time to be in Portsmouth. The temperatures are nice, and there’s not too much rain.
Average temperatures and precipitation
This chart shows the average daily maximum and minimum temperatures (in degrees Celsius) and precipitation (in millimeters) in May for Portsmouth, New Hampshire. A low precipitation value usually indicates little to no rainfall on that day in recent years, while a higher value suggests more frequent rainfall.
Temperature records
With 34°C in 2017, Portsmouth reached the highest temperature in May over the past 10 years. The lowest daytime temperature in this month was 5°C in 2020. The extreme nighttime temperatures ranged from a lowest recorded value of 0°C to a highest value of 22°C.
Rainfall amount
In May, there is an average of 62 mm of precipitation, spread over 10 days. The wind speed is around 4 Bft, mostly coming from the South.
Daily weather in May for Portsmouth
Click on any day in May to get detailed info about the usual weather on that day in Portsmouth. Check out the historical temperatures and precipitation over the past 10 years on this day.
May weather comparison
| Portsmouth | New York | |
|---|---|---|
| Average temperature | 20°C | 22°C |
| Max. temperature | 25°C | 28°C |
| Min. temperature | 5°C | -5°C |
| Total precipitation | 62 mm | 105 mm |
| Rainy days | 10 days | 14 days |
Start of May
The month of May starts in Portsmouth with cool temps, averaging around 17°C during the day and nights around 8°C.
Mid May
By mid-May, daytime temps rise to around 21°C, with nights around 10°C. There’s a chance of some showers during this time, but plenty of dry and sunny days too.
End of May
By the end of May, the average daytime temperature in Portsmouth is around 22°C, while nighttime temps are about 12°C. A shower might pop up, but overall, the weather will be dry and sunny.
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UV index
The UV index is a maximum of 9 this month. That's a very high value on the intensity scale of 1 to 11. Unprotected skin can burn within 10-15 minutes.
Check out the climate of Portsmouth for all months and discover the best travel time
Temperature charts
These charts show the average temperatures in May in Portsmouth, New Hampshire. The temperatures are shown in degrees Celsius and are calculated based on data from the past 10 years.
Daily Temperature in May in Portsmouth
Temperature in May in Portsmouth over the years
Precipitation charts
These charts show the average amount of precipitation in May in Portsmouth, New Hampshire. Precipitation is always measured as water, even when it falls as snow or hail The amount of precipitation is displayed in millimeters, while snowfall is shown in centimeters.
Daily Precipitation in May in Portsmouth
Total precipitation in May in Portsmouth over the years
Daily UV index in May in Portsmouth
This chart shows the average daily UV index in May in Portsmouth, with the UV index ranging from 0 to a maximum of 11. The bottom of the chart shows the days of the month. Based on historical data, this chart provides an idea of the daily UV radiation levels you can expect.
Weather experiences in May in Portsmouth
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Average weather in Portsmouth by month
Click on a month below to see detailed weather info for Portsmouth. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.