National Weather Service Forecast for: Portsmouth NH
Issued by: National Weather Service Gray/Portland, ME
Updated: 2:25 am EDT Aug 20, 2026
 
Today

Today: Increasing clouds, with a high near 83. Calm wind becoming southeast around 5 mph in the afternoon.
Increasing
Clouds
 Tonight

Tonight: A 30 percent chance of showers, mainly before 10pm. Mostly cloudy, with a low around 60. Calm wind. New precipitation amounts of less than a tenth of an inch possible.
Chance
Showers
 Friday

Friday: A chance of showers between 10am and 1pm. Mostly sunny, with a high near 76. Northeast wind around 5 mph. Chance of precipitation is 30%.
Chance
Showers
 Friday
Night
Friday Night: A 30 percent chance of showers after 3am. Increasing clouds, with a low around 59. Calm wind.
Partly Cloudy
then Chance
Showers
 Saturday

Saturday: Showers, mainly after 11am. High near 74. Northeast wind 5 to 10 mph. Chance of precipitation is 80%.
Showers

 Saturday
Night
Saturday Night: Showers, mainly before 2am. Low around 61. Chance of precipitation is 80%.
Showers

 Sunday

Sunday: A 40 percent chance of showers. Mostly cloudy, with a high near 80.
Chance
Showers
 Sunday
Night
Sunday Night: A 40 percent chance of showers before midnight. Mostly cloudy, with a low around 62.
Chance
Showers then
Mostly Cloudy
 Monday

Monday: Mostly sunny, with a high near 82.
Mostly Sunny
Hi 83 °F Lo 60 °F Hi 76 °F Lo 59 °F Hi 74 °F Lo 61 °F Hi 80 °F Lo 62 °F Hi 82 °F

 

Today
 
 Increasing clouds, with a high near 83. Calm wind becoming southeast around 5 mph in the afternoon.
Tonight
 
 A 30 percent chance of showers, mainly before 10pm. Mostly cloudy, with a low around 60. Calm wind. New precipitation amounts of less than a tenth of an inch possible.
Friday
 
 A chance of showers between 10am and 1pm. Mostly sunny, with a high near 76. Northeast wind around 5 mph. Chance of precipitation is 30%.
Friday Night
 
 A 30 percent chance of showers after 3am. Increasing clouds, with a low around 59. Calm wind.
Saturday
 
 Showers, mainly after 11am. High near 74. Northeast wind 5 to 10 mph. Chance of precipitation is 80%.
Saturday Night
 
 Showers, mainly before 2am. Low around 61. Chance of precipitation is 80%.
Sunday
 
 A 40 percent chance of showers. Mostly cloudy, with a high near 80.
Sunday Night
 
 A 40 percent chance of showers before midnight. Mostly cloudy, with a low around 62.
Monday
 
 Mostly sunny, with a high near 82.
Monday Night
 
 Mostly clear, with a low around 58.
Tuesday
 
 Sunny, with a high near 81.
Tuesday Night
 
 Mostly clear, with a low around 58.
Wednesday
 
 Sunny, with a high near 82.

 

Forecast from NOAA-NWS for Portsmouth NH.