What August feels like in Lisbon
Summer peaks in August: no month in Lisbon is warmer. Warm daytime weather invites long lunches outside and evening strolls. After sunset it cools off noticeably — nights stay mild. Some humidity hangs in the air, noticeable when the sun is strong.
Rain in Lisbon in August
Dry weather dominates, and an umbrella can mostly stay packed. When it rains, it is usually light: about 2.5 mm (0.1 in) per rainy day, more drizzle than downpour. That is lighter than the city's yearly norm of about 7.7 mm per rainy day. It is among the three driest months of the year.
Daylight and sunshine in August
Mid-month, Lisbon gets 13 h 43 min of daylight, from sunrise near 6:50 am to sunset near 8:33 pm. Days are getting shorter: 55 min less daylight than in mid-July. Measured sunshine covers about 92% of the daylight — skies are mostly clear.
How August compares to the rest of the year
Ranked by average high, August comes out as the warmest month in Lisbon. Afternoons run 0.7°C (1.3°F) warmer than in July, with about the same rain. From here temperatures start to ease, beginning in September. September averages a high of 25.5°C (77.9°F).
Who August suits
- Sightseeing: a good fit — daytime temperatures are fine for walking around.
- Parks & outdoor: less ideal — afternoons are too warm to linger outside.
- Beach: a good fit — warm and mostly dry on the coast.
Tips for visiting Lisbon in August
Versatile Layers
Days are noticeably warmer than nights — layers you can add or remove.
Sunglasses
Plenty of sun, so bring sunglasses and a cap.
Quick questions
How warm is Lisbon in August?
Expect around 27.6°C (81.7°F) in the afternoon and 18.6°C (65.5°F) at night, which most visitors would call warm.
Does it rain a lot in Lisbon in August?
Hardly — only about 1 rainy days and 3 mm for the whole month.
What should I wear in Lisbon in August?
The numbers point to versatile layers and sunglasses. Evenings feel similar to the day, so the same clothes work from morning to night.
Is August or September better for visiting Lisbon?
September, narrowly: it ranks #4 of 12 among Lisbon's months, against #5 for the other. September is cooler and has more rainy days.