Hot in Aug
31°C average high
avg high · 23° at night
25°C+ on almost every day
Portugal
Lisbon weather in August
Is it warm? Yes. August in Lisbon is warm: afternoons average 28°C and nights 18°C. Most days (80%) peak between 24°C and 32°C.
Warm · average high
28°C
25°C or more on about eight in ten days; 20°C or more on almost every day.
- Average low18°overnight
- Sea17°average, 2023–2025
- Rainy days02 mm in the month
- SkySome cloud26% cloud · 64% clear days
How warm it really gets
Every August afternoon from 2011–2025: 465 days. Most (80%) peaked between 24° and 32°.
August, year by year
The average August high in each year. The warmest, 2018, averaged 31°C; the coolest, 2014, 25°C.
Compared with home
Average August highs. Rain is rare: less than one wet day in a typical month.
- Lisbon28°
- London22°
- Manchester19°
- Dublin19°
- Cork19°
- Belfast18°
- Glasgow18°
Warmer in August, not much further
Flying times are estimates from Dublin; Lisbon is about 2h 30m.
Hot in Aug
31°C average high
avg high · 22° at night
25°C+ on almost every day
Hot in Aug
31°C average high
avg high · 24° at night
25°C+ on almost every day
Air: ERA5 reanalysis via Open-Meteo, 2011–2025. Sea: Copernicus Marine analysis via Open-Meteo, 2023–2025. Rainy day = 2 mm or more. Clear day = average cloud cover of 30% or less. These are averages of past weather, not a forecast. Methodology