Climate averages 1991–2020
Porto weather
in August.
A warm, fairly dry month: the warmest and the 2nd driest of the year. Meets the pleasant-weather rule
Long-term climate patterns, not a forecast for a particular trip.
August is a warm month in Porto: daytime highs average 26.2°C and nights cool to about 17.2°C. By daytime temperature it is the warmest month of the year.
Expect about 29 mm of rain on roughly 5 days, which makes August a fairly dry month (the 2nd driest of the 12 months). Daylight, from sunrise to sunset, lasts about 13 h 49 min on an average August day.
The nearest other city in this atlas is Braga (47 km away). In August its highs average 26.4°C, about as warm as Porto, with 39 mm of rain.
Among the 12 cities listed in Portugal, Porto ranks joint 9th of 12 for the warmest August highs and 11th of 12 for the driest August (rainfall, lowest first). The mean August high of those 12 cities is 26.8°C; Porto is 0.6°C cooler than that mean.
From August to September, average highs fall by 2.0°C to 24.1°C, and monthly rainfall rises from 29 mm to 64 mm.
The annual picture
August in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Porto climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 12.8°C6.3°C | 6.3°C | 150 | 12.2 | 9.610 h |
| February | 13.9°C6.3°C | 6.3°C | 103 | 9.6 | 10.611 h |
| March | 16.3°C8.1°C | 8.1°C | 121 | 10.2 | 11.912 h |
| April | 17.5°C9.7°C | 9.7°C | 121 | 11.8 | 13.313 h |
| May | 20.1°C12.3°C | 12.3°C | 101 | 11.1 | 14.514 h |
| June | 23.2°C15.0°C | 15.0°C | 40 | 6.3 | 15.115 h |
| July | 25.6°C16.7°C | 16.7°C | 23 | 4.0 | 14.815 h |
| August, selected | 26.2°C17.2°C | 17.2°C | 29 | 4.5 | 13.814 h |
| September | 24.1°C15.7°C | 15.7°C | 64 | 6.6 | 12.513 h |
| October | 20.1°C13.1°C | 13.1°C | 166 | 12.7 | 11.111 h |
| November | 15.7°C9.6°C | 9.6°C | 163 | 12.9 | 9.910 h |
| December | 13.5°C7.4°C | 7.4°C | 167 | 12.4 | 9.39 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
August in nearby cities
- Braga in AugustPortugal · 47 kmHigh 26.4°C · Low 15.4°C · 39 mm rain
- Aveiro in AugustPortugal · 56 kmHigh 27.3°C · Low 17.2°C · 17 mm rain
- Viseu in AugustPortugal · 80 kmHigh 27.9°C · Low 15.8°C · 26 mm rain
- Coimbra in AugustPortugal · 106 kmHigh 28.9°C · Low 16.5°C · 14 mm rain
- Vigo in AugustSpain · 121 kmHigh 23.9°C · Low 16.1°C · 49 mm rain
- Pontevedra in AugustSpain · 143 kmHigh 25.4°C · Low 16.4°C · 48 mm rain
- Ourense in AugustSpain · 146 kmHigh 27.1°C · Low 15.4°C · 27 mm rain
- Leiria in AugustPortugal · 157 kmHigh 27.1°C · Low 16.9°C · 9.6 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Porto) is explained once on the Porto year overview and on the Sources, method and limits page.