Lisbon in August
In August, Lisbon has 5.8 mm (0.23 in) of rain, a daily high of 28.1 °C (82.6 °F) and a daily low of 19.0 °C (66.2 °F), as 1991-2020 model estimates; figures in brackets are converted. The daily high is a model estimate, adjusted against station records.
Last updated : first sourced version.
Best time to visit Lisbon: August is a near miss for our rule: days are 0.1 °C over our 28 °C (model estimates). Expect 0.7 rain days (model estimate) and days that shorten by 1 h 05 min.
What August is like in Lisbon
- On late afternoons in August, the Castelo de São Jorge opens its gates, and music takes over its walls. Source: Castelo de São Jorge (EGEAC), checked .
- In August, black-headed gulls can be seen at Terreiro do Paço. By now the adults have lost their brown hoods. Source: Wilder, checked .
- Until the end of August, plates of snails in each house's own sauce are served in Benfica and Alvalade. Source: NiT, checked .
Key figures
Weather in August, 1991-2020 model estimates
- Daily high
- 28.1 °C (82.6 °F)
- Daily low
- 19.0 °C (66.2 °F)
- Rain
- 5.8 mm (0.23 in) in the month
- Sunshine
- no data
Model estimate 1991-2020, not a weather station: ERA5-Land model estimates (Copernicus), computed by City by Month for the grid cell nearest the city. Daily high and Days with rain: model estimate, adjusted against station records. Licence: CC BY 4.0. Checked . How we make and test model estimates
Model estimate for the ERA5-Land grid cell at 38.7° N, 9.1° W, 4 km from the city centre point.
How we define and convert these figures
Notes. Sunshine: Not in our ERA5-Land estimates.
Daylight on 15 August 2026
- Sunrise
- 06:50 local time
- Sunset
- 20:31 local time
- Day length
- 13 h 41 min
Day length 1-31 August: 14 h 09 min to 13 h 04 min, -1 h 05 min.
Source: NOAA Solar Calculator equations, checked .
Month by month
Each month: daily high in °C, then rain in mm, 1991-2020 model estimates.
ERA5-Land model estimates 1991-2020, as above, checked .
This month against the year
| Measure | August | Rank |
|---|---|---|
| Daily high | 28.1 °C | warmest |
| Daily low | 19.0 °C | warmest |
| Rain | 5.8 mm | 2nd driest |
| Sunshine | no data | no data |
| Day length | 13 h 41 min | 4th longest |
Equal values share a rank. How we rank months
Lisbon in August, on average: 0.7 rain days (1 mm or more). Model estimate, adjusted against station records.
ERA5-Land model estimates 1991-2020, as above, checked .
Day length: NOAA solar equations, checked .
Public holidays this month
| Date | Holiday |
|---|---|
| Saturday | Assumption Day diariodarepublica.pt |
Typed from the official list and re-checked, .
August 2027: no data. No official page gives the 2027 Easter and Corpus Christi dates yet.
English names are from the holidays library where the official list gives none. How we check holidays
Source: Official public holiday list (dgaj.justica.gov.pt), checked ; holidays Python library, checked . Library: holidays 0.105.
Same month in 8 model-estimate cities
Lisbon is warmer than 3 of our 8 model-estimate cities in August by mean daily high. How we rank cities
Closest high and low in August: Porto (1.1 °C apart), Istanbul (1.7), Mumbai (3.5).
| City | Gap from Lisbon, °C | High, °C | Low, °C | Rain, mm | Sunshine, hours |
|---|---|---|---|---|---|
| Lisbon (this page) | — | 28.1 | 19.0 | 5.8 | no data |
| Porto (closest) | 1.1 | 27.7 | 17.3 | 26.3 | no data |
| Istanbul (closest) | 1.7 | 29.1 | 21.4 | 23.7 | no data |
| Mumbai (closest) | 3.5 | 28.9 | 25.1 | no data | no data |
| Bangkok | 5.6 | 32.6 | 25.6 | no data | no data |
| Delhi | 6.3 | 33.7 | 26.0 | no data | no data |
| Sydney | 9.3 | 18.9 | 9.7 | 50.3 | no data |
| Melbourne | 12.6 | 15.3 | 6.7 | 59.5 | no data |
Sources (1991-2020): ERA5-Land model estimates, checked . Each city's page names its grid cell. All sources in full on Methodology.
Sources
- Attribution: Copernicus Climate Change Service (2025): ERA5 Land hourly time-series data from 1950 to present. Copernicus Climate Change Service (C3S) Climate Data Store (CDS). DOI: 10.24381/ee82e357. Accessed on the check date shown. Generated using or contains modified Copernicus Climate Change Service information 2025. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains. Licence: CC BY 4.0. Checked .
- NOAA Solar Calculator equations, computed locally, NOAA Global Monitoring Laboratory (method); City by Month (computation). Attribution: Computed with the NOAA Solar Calculator method (no NOAA endorsement implied). Licence: Method, not data. Checked .
- holidays Python library, run locally. Attribution: holidays library, Vacanza team. Licence: MIT. Checked .
Official sources
Cite this page: City by Month. "Lisbon in August: weather, daylight, holidays". https://citybymonth.com/cities/portugal/lisbon/august/. Last updated 8 November 2026.