Portsmouth weather in August 2025

Expect 88°F daytime maximum temperatures in the shade with on average 8 hours of sunshine per day in Portsmouth in August. Check more long-term weather averages for Portsmouth in August before you book your next holiday to Dominica in 2025/2026.

  • 88°F maximum daytime temperature in August in Portsmouth88
    88°F max day temperature
  • 8 hours of sunshine per day
  • 20 days with some rainfall in August in Portsmouth20
    20 days with some rainfall
  • 75°F minimum night-time temperature in August in Portsmouth75
    75°F min night temperature
  • 13 hours of daylight per day in August in Portsmouth13
    13 hours of daylight per day
  • High heat & humidity in August in PortsmouthH
    High heat & humidity
  • 9.6 inches monthly rainfall in August in Portsmouth9.6
    9.6 inches of monthly rainfall
  • UV (maximum) index 11+ (Extreme) in August in Portsmouth11
    11+ (Extreme) UV index
  • 82°F sea temperature in August in Portsmouth82
    82°F sea temperature

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The August weather guide for Dominica (Portsmouth) shows long term weather averages processed from data supplied by CRU (University of East Anglia), the Met Office & the Netherlands Meteorological Institute. Find out more about our data sources.

Metric (°C)  |  Imperial (°F)

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How hot is it in Portsmouth in August?

Daytime temperatures usually reach 88°F in Portsmouth in August with high heat and humidity, falling to 75°F at night.

How sunny is it in Portsmouth in August?

There are normally 8 hours of bright sunshine each day in Portsmouth in August - that's 62% of daylight hours.

How warm is the sea around Portsmouth in August?

The average sea temperature around Portsmouth in August is 82°F.

Does it rain in Portsmouth in August?

There are usually 20 days with some rain in Portsmouth in August and the average monthly rainfall is 9.6 inches.

What is the chance of a hurricane in Portsmouth in August?

On average less than 1 day in August in Portsmouth is likely to be affected by the passage of one or more tropical storms.

Portsmouth August sunrise & sunset times

Browse the sunrise and sunset times for Portsmouth in August 2025. Select a month to view Portsmouth sunrise and sunset times for the next 12 months.

JanFebMarAprMayJunJulAugSepOctNovDec

Date Sunrise times Sunset times
Friday, 1st August 2025 05:48 18:36
Saturday, 16th August 2025 05:51 18:29
Sunday, 31st August 2025 05:53 18:19

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