Portsmouth weather live forecast

Today's maximum temperature in Portsmouth is expected to be 79°F. Select a day from the live weather forecast for Portsmouth, New Hampshire, USA for more weather parameters.

5-day weather forecast updated at 04:04 on Sunday 17th August 2025 GMT

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The 5-day weather forecast for New Hampshire (Portsmouth) is provided by the Swiss meteorological agency, meteoblue. Find out more about our data sources.

Portsmouth weather forecast by day

Below are the detailed weather forecasts for Portsmouth for the next 5 days.

Portsmouth weather for Saturday 16th August 2025

Expect clear skies in Portsmouth, New Hampshire with a maximum temperature of 79°F, low levels of heat & humidity, maximum UV of 7 (High) and 14 hours of bright sunshine. There are 0 mm of rainfall expected and a gentle breeze of 9 mph from the south-east.

  • 79°F maximum temperature79
    °F maximum temperature
  • 57°F minimum temperature57
    °F minimum temperature
  • Clear skies
    clear skies
  • 14 hours of bright sunshine14
    hours of sunshine
  • UV (maximum) index 7 (High)7
    UV index (High)
  • 0 mm of rainfall expected0
    mm of rainfall expected
  • Low heat & humidityL
    low heat & humidity
  • Gentle breeze of 9 mph from the South-East9
    mph wind from SE

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Portsmouth weather for Sunday 17th August 2025

Expect isolated thunderstorms in Portsmouth, New Hampshire with a maximum temperature of 86°F, moderate levels of heat & humidity, maximum UV of 6 (High) and 7 hours of bright sunshine. There are 0-2 mm of rainfall expected with 42% chance of some rain and a gentle breeze of 10 mph from the south-west.

  • 86°F maximum temperature86
    °F maximum temperature
  • 66°F minimum temperature66
    °F minimum temperature
  • Isolated thunderstorms
    isolated thunderstorms
  • 7 hours of bright sunshine7
    hours of sunshine
  • UV (maximum) index 6 (High)6
    UV index (High)
  • 42% chance of some rain42
    % chance of some rain
  • 0-2 mm of rainfall expected<2
    mm of rainfall expected
  • Moderate heat & humidityM
    moderate heat & humidity
  • Gentle breeze of 10 mph from the South-West10
    mph wind from SW

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Portsmouth weather for Monday 18th August 2025

Expect scattered clouds in Portsmouth, New Hampshire with a maximum temperature of 70°F, maximum UV of 7 (High) and 12 hours of bright sunshine. There are 0 mm of rainfall expected and a gentle breeze of 11 mph from the north-east.

  • 70°F maximum temperature70
    °F maximum temperature
  • 55°F minimum temperature55
    °F minimum temperature
  • Scattered clouds
    scattered clouds
  • 12 hours of bright sunshine12
    hours of sunshine
  • UV (maximum) index 7 (High)7
    UV index (High)
  • 0 mm of rainfall expected0
    mm of rainfall expected
  • 70°F wind chill70
    °F wind chill
  • Gentle breeze of 11 mph from the North-East11
    mph wind from NE

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Portsmouth weather for Tuesday 19th August 2025

Expect broken clouds in Portsmouth, New Hampshire with a maximum temperature of 70°F, maximum UV of 7 (High) and 6 hours of bright sunshine. There are 0 mm of rainfall expected and a gentle breeze of 8 mph from the south-east.

  • 70°F maximum temperature70
    °F maximum temperature
  • 54°F minimum temperature54
    °F minimum temperature
  • Broken clouds
    broken clouds
  • 6 hours of bright sunshine6
    hours of sunshine
  • UV (maximum) index 7 (High)7
    UV index (High)
  • 0 mm of rainfall expected0
    mm of rainfall expected
  • No heat & humidity0
    no heat & humidity
  • Gentle breeze of 8 mph from the South-East8
    mph wind from SE

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Portsmouth weather for Wednesday 20th August 2025

Expect mostly cloudy with rain in Portsmouth, New Hampshire with a maximum temperature of 68°F, maximum UV of 4 (Moderate) and 2 hours of bright sunshine. There are 5-10 mm of rainfall expected with 52% chance of some rain and a light breeze of 7 mph from the south-east.

  • 68°F maximum temperature68
    °F maximum temperature
  • 59°F minimum temperature59
    °F minimum temperature
  • Mostly cloudy with rain
    mostly cloudy with rain
  • 2 hours of bright sunshine2
    hours of sunshine
  • UV (maximum) index 4 (Moderate)4
    UV index (Moderate)
  • 52% chance of some rain52
    % chance of some rain
  • 5-10 mm of rainfall expected<10
    mm of rainfall expected
  • No heat & humidity0
    no heat & humidity
  • Light breeze of 7 mph from the South-East7
    mph wind from SE

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