National Weather Service Forecast for: Portsmouth NH
Issued by: National Weather Service Gray/Portland, ME
Updated: 3:24 pm EDT Jul 27, 2025
 
This
Afternoon
This Afternoon: A 50 percent chance of showers and thunderstorms, mainly before 5pm. Widespread haze. Mostly cloudy, with a high near 76. South wind around 10 mph. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Chance
Showers
 Tonight

Tonight: Widespread haze before 4am, then widespread haze after 5am. Partly cloudy, with a low around 66. South wind around 5 mph becoming calm in the evening.
Haze

 Monday

Monday: Widespread haze before 7am, then widespread haze after 8am. Sunny, with a high near 88. Calm wind becoming southeast around 5 mph in the afternoon.
Haze

 Monday
Night
Monday Night: Mostly clear, with a low around 64. South wind around 5 mph becoming calm in the evening.
Mostly Clear

 Tuesday

Tuesday: Sunny and hot, with a high near 92. Calm wind becoming southwest around 5 mph in the afternoon.
Hot

 Tuesday
Night
Tuesday Night: Partly cloudy, with a low around 67.
Partly Cloudy

 Wednesday

Wednesday: A 30 percent chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 87.
Mostly Sunny
then Chance
T-storms
 Wednesday
Night
Wednesday Night: A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 66.
Chance
T-storms
 Thursday

Thursday: A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 78.
Chance
T-storms
Hi 76 °F Lo 66 °F Hi 88 °F Lo 64 °F Hi 92 °F Lo 67 °F Hi 87 °F Lo 66 °F Hi 78 °F

Hazardous Weather Outlook
Heat Advisory
 

This Afternoon
 
 A 50 percent chance of showers and thunderstorms, mainly before 5pm. Widespread haze. Mostly cloudy, with a high near 76. South wind around 10 mph. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Tonight
 
 Widespread haze before 4am, then widespread haze after 5am. Partly cloudy, with a low around 66. South wind around 5 mph becoming calm in the evening.
Monday
 
 Widespread haze before 7am, then widespread haze after 8am. Sunny, with a high near 88. Calm wind becoming southeast around 5 mph in the afternoon.
Monday Night
 
 Mostly clear, with a low around 64. South wind around 5 mph becoming calm in the evening.
Tuesday
 
 Sunny and hot, with a high near 92. Calm wind becoming southwest around 5 mph in the afternoon.
Tuesday Night
 
 Partly cloudy, with a low around 67.
Wednesday
 
 A 30 percent chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 87.
Wednesday Night
 
 A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 66.
Thursday
 
 A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 78.
Thursday Night
 
 A 30 percent chance of showers before 2am. Mostly cloudy, with a low around 59.
Friday
 
 Mostly sunny, with a high near 76.
Friday Night
 
 Mostly clear, with a low around 57.
Saturday
 
 Sunny, with a high near 78.
Saturday Night
 
 Mostly clear, with a low around 58.
Sunday
 
 Sunny, with a high near 83.

 

Forecast from NOAA-NWS for Portsmouth NH.