August in Lisbon features dry warm days and comfortable nights, however, about 4-5 afternoons will feel muggy.
Daytime high temperatures during August tend to be near 28-29 C (82-84 F), however, about 5 afternoons will reach up to 32 C (90 F) or more.
The record high temperature for Lisbon during August is 42.2 C (107.6 F).
Late night and early morning lows tend to average 18-19 C (64-66 F, however, a few of the cooler mornings can dip down near 16C (61 F).
The record low temperature for Lisbon during August is 11.2 C (52.2 F).
Sun and Rain
August in Lisbon is sunny with some increase in cloudiness likely near the end of the month.
Overall, you can expect about 23 sunny, 3 partly sunny, and 5 mostly cloudy days.
About 3-4 days record some rainfall, however, only 1 day, on average, records 1 mm (0.04 inches) or more.
The number of daylight hours decreases this month from about 14.2 hours on the 1st to about 13.1 hours by the 31st.
Wind conditions this month are mostly gentle to moderate averaging 12-28 kph (8-18 mph).
Lisbon lies along the Atlantic coast and has several stunning nearby beaches.
Ocean temperatures tend to be somewhat on the cool side during August, averaging near 19 C (66-67 F).
What to Wear in Lisbon During August?
Lightweight and comfortable summer attire like jeans, tees, denim cutoffs work well in Lisbon during this month.
A few nights and early mornings can still be a bit chilly so also bring along a light sweater or windbreaker.
Don’t forget sunglasses and sunscreen, as well as a good pair of walking shoes.
Things to Do in Lisbon During August
There should be plenty of sunny days to enjoy this month, which makes it the perfect time to consider taking a pay-what-you-wish walking tour in Lisbon.
If you're visiting with family, this might be one of the best times to think about taking your kids to the Lisbon Zoo, as the weather will be absolutely perfect.
Alternatively, a trip to the Oceanarium might also be in order, because this would allow you to get out of the summer heat for a bit by wandering around their giant aquarium.
When the sun sets, consider heading out to a live Fado show to see one of the most traditional forms of music to come out of Lisbon.
For even more ideas, make sure to read our full post covering things to do in Lisbon.