Portsmouth weather live forecast

Today's maximum temperature in Portsmouth is expected to be 26°C. Select a day from the live weather forecast for Portsmouth, New Hampshire, USA for more weather parameters.

5-day weather forecast updated at 04:03 on Saturday 16th 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 26°C, maximum UV of 7 (High) and 13 hours of bright sunshine. There are 0 mm of rainfall expected and a gentle breeze of 15 kph from the south-east.

  • 26°C maximum temperature26
    °C maximum temperature
  • 15°C minimum temperature15
    °C minimum temperature
  • Clear skies
    clear skies
  • 13 hours of bright sunshine13
    hours of sunshine
  • UV (maximum) index 7 (High)7
    UV index (High)
  • 0 mm of rainfall expected0
    mm of rainfall expected
  • 26°C wind chill26
    °C wind chill
  • Gentle breeze of 15 kph from the South-East15
    kph 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 29°C, moderate levels of heat & humidity, maximum UV of 7 (High) and 9 hours of bright sunshine. There are 0-2 mm of rainfall expected with 26% chance of some rain and a gentle breeze of 15 kph from the south-west.

  • 29°C maximum temperature29
    °C maximum temperature
  • 18°C minimum temperature18
    °C minimum temperature
  • Isolated thunderstorms
    isolated thunderstorms
  • 9 hours of bright sunshine9
    hours of sunshine
  • UV (maximum) index 7 (High)7
    UV index (High)
  • 26% chance of some rain26
    % chance of some rain
  • 0-2 mm of rainfall expected<2
    mm of rainfall expected
  • Moderate heat & humidityM
    moderate heat & humidity
  • Gentle breeze of 15 kph from the South-West15
    kph wind from SW

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Portsmouth weather for Monday 18th August 2025

Expect sunshine and showers in Portsmouth, New Hampshire with a maximum temperature of 22°C, maximum UV of 7 (High) and 9 hours of bright sunshine. There are 0-2 mm of rainfall expected with 3% chance of some rain and a gentle breeze of 16 kph from the north.

  • 22°C maximum temperature22
    °C maximum temperature
  • 14°C minimum temperature14
    °C minimum temperature
  • Sunshine and showers
    sunshine and showers
  • 9 hours of bright sunshine9
    hours of sunshine
  • UV (maximum) index 7 (High)7
    UV index (High)
  • 3% chance of some rain3
    % chance of some rain
  • 0-2 mm of rainfall expected<2
    mm of rainfall expected
  • 22°C wind chill22
    °C wind chill
  • Gentle breeze of 16 kph from the North16
    kph wind from N

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Portsmouth weather for Tuesday 19th August 2025

Expect mostly cloudy with light rain in Portsmouth, New Hampshire with a maximum temperature of 20°C, maximum UV of 5 (Moderate) and no hours of bright sunshine. There are 0-2 mm of rainfall expected with 25% chance of some rain and a light breeze of 12 kph from the south-east.

  • 20°C maximum temperature20
    °C maximum temperature
  • 14°C minimum temperature14
    °C minimum temperature
  • Mostly cloudy with light rain
    mostly cloudy with light rain
  • No hours of bright sunshine0
    hours of sunshine
  • UV (maximum) index 5 (Moderate)5
    UV index (Moderate)
  • 25% chance of some rain25
    % chance of some rain
  • 0-2 mm of rainfall expected<2
    mm of rainfall expected
  • 20°C wind chill20
    °C wind chill
  • Light breeze of 12 kph from the South-East12
    kph wind from SE

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Portsmouth weather for Wednesday 20th August 2025

Expect cloudy with some rain in Portsmouth, New Hampshire with a maximum temperature of 20°C, maximum UV of 1 (Low) and no hours of bright sunshine. There are 5-10 mm of rainfall expected with 48% chance of some rain and a gentle breeze of 13 kph from the east.

  • 20°C maximum temperature20
    °C maximum temperature
  • 13°C minimum temperature13
    °C minimum temperature
  • Cloudy with some rain
    cloudy with some rain
  • No hours of bright sunshine0
    hours of sunshine
  • UV (maximum) index 1 (Low)1
    UV index (Low)
  • 48% chance of some rain48
    % chance of some rain
  • 5-10 mm of rainfall expected<10
    mm of rainfall expected
  • 20°C wind chill20
    °C wind chill
  • Gentle breeze of 13 kph from the East13
    kph wind from E

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Metric (°C / mm)  |  Imperial (°F / inches)

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