Warm in May
24°C average high
avg high · 15° at night
25°C+ on 4 in 10 days
Portugal
Lisbon weather in May
Is it warm? Mostly. May in Lisbon is mild: afternoons average 22°C and nights 14°C. Most days (80%) peak between 17°C and 28°C.
Mild · average high
22°C
25°C or more on about three in ten days; 20°C or more on about seven in ten days.
- Average low14°overnight
- Sea16°average, 2023–2025
- Rainy days340 mm in the month
- SkySome cloud43% cloud · 38% clear days
How warm it really gets
Every May afternoon from 2011–2025: 465 days. Most (80%) peaked between 17° and 28°.
May, year by year
The average May high in each year. The warmest, 2022, averaged 25°C; the coolest, 2016, 19°C.
Compared with home
Average May highs. Expect rain on about 3 days (40 mm in a typical month).
- Lisbon22°
- London17°
- Manchester16°
- Cork15°
- Dublin15°
- Glasgow15°
- Belfast14°
Warmer in May, not much further
Flying times are estimates from Dublin; Lisbon is about 2h 30m.
Hot in May
28°C average high
avg high · 15° at night
25°C+ on 7 in 10 days
Mild in May
24°C average high
avg high · 16° at night
25°C+ on 3 in 10 days
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