Published 23 October 2026 · Climate data: IPMA, station Lisboa / Gago Coutinho, normals 1991 to 2020 · Listing data: Inside Airbnb, June 2026
Is Lisbon hot in August?
August is the hottest month in Lisbon. The official climate normal of IPMA, the Portuguese weather institute, gives an average daily high of 29.0 °C (84 °F) and an average low of 18.5 °C (65 °F) for the city station at Gago Coutinho. On an average August, 27.7 days reach 25 °C, 10.7 days reach 30 °C and 2.8 days reach 35 °C. Those are averages over thirty years: a heatwave can put several 35 °C days in a single week, and the hottest day on record at this station was 44.0 °C (111 °F) on 4 August 2018.
Most days feel pleasant in the shade thanks to the Atlantic breeze. What catches visitors out is the late afternoon sun on west facing streets and the heat stored in old stone buildings, which keeps apartments warm long after sunset.
What is the weather like in Lisbon in August?
Dry, sunny and warm. The IPMA normal for August is 5.0 mm of rain in the whole month and one day with at least 1 mm, so plan for sun, not showers. Nights stay mild: the average low is 18.5 °C, and on about 6 nights a month the temperature does not drop below 20 °C. Those warm nights tend to come in runs during heatwaves, which is exactly when sleeping in a flat without cooling gets hard.
| Month | Average high | Days at 30 °C or more | Days at 35 °C or more | Nights at 20 °C or more | Rain |
|---|---|---|---|---|---|
| June | 26.1 °C (79 °F) | 6.2 | 0.9 | 2.6 | 13.4 mm |
| July | 28.3 °C (83 °F) | 9.1 | 2.5 | 4.4 | 2.9 mm |
| August | 29.0 °C (84 °F) | 10.7 | 2.8 | 5.9 | 5.0 mm |
| September | 26.8 °C (80 °F) | 6.5 | 0.6 | 2.9 | 35.9 mm |
Source: IPMA, Normal Climatológica Lisboa / Gago Coutinho 1991 to 2020. Days and nights are monthly averages.
Do Lisbon apartments and Airbnbs have air conditioning in August?
Often they do not. In the Inside Airbnb snapshot of June 2026, 58.5% of the 24,876 listings in the Lisbon region did not list air conditioning among their amenities, and inside Lisbon city it was 55.5%. The cheaper the listing, the less likely it is cooled: under €80 a night, 82.5% list no air conditioning. Most Lisbon housing was simply built without it, and the historic centre often does not allow outdoor units on the facade.
So check the amenities list for "air conditioning" before you book, not the photos, and do not count on a fan being enough on a 30 °C evening. The full breakdown by neighbourhood and price is in our Lisbon Airbnb air conditioning data.
How do you sleep in Lisbon when it is this hot?
Keep the heat out during the day and let it out at night. Close shutters and curtains on the sunny side from the morning, open windows on opposite sides of the flat after sunset to get a through draught, and run a fan towards an open window rather than at your bed. A cool shower before bed helps more than a cold drink. On the warm nights in a heatwave, when it stays above 20 °C, these tricks stop working in a top floor or west facing flat. That is when a portable air conditioner in the bedroom makes the difference: it plugs into a normal socket and vents through the window with a sealing kit, without drilling and without asking the landlord. Our guide to sleeping through Lisbon heat goes room by room.
Is August a good time to visit Lisbon?
Yes, if you plan around the heat. Mornings and evenings are lovely, the city is lively and rain is rare. Do the steep walks in Alfama and Graça before 11:00, spend the hottest hours in museums or by the river, and keep sunset for a miradouro. The one thing that can spoil the trip is a room that never cools down, so treat air conditioning as a real criterion when you book. If you already booked a flat without it, read what to do when your Lisbon Airbnb has no AC, or have a unit delivered to your door.
Quick answers
What is the average temperature in Lisbon in August?
The average daily high is 29.0 °C (84 °F) and the average low 18.5 °C (65 °F), with a daily mean of 23.8 °C, according to the IPMA climate normals for 1991 to 2020.
Does it rain in Lisbon in August?
Hardly. The normal is 5.0 mm for the whole month and about one day with at least 1 mm of rain.
Is July or August hotter in Lisbon?
August, slightly: 29.0 °C average high against 28.3 °C in July, and 10.7 days at 30 °C or more against 9.1.
Can I rent an air conditioner for a short stay in Lisbon?
Yes. AC Rental Lisbon delivers a portable air conditioner to your flat from €40 a day or €210 a week, plus €25 for delivery, setup and collection and a €100 refundable deposit. Same-day delivery when you confirm before 16:00.
