Climate averages 1991–2020
Porto weather
in December.
A cool, wet month: the 11th warmest and the wettest of the year.
Long-term climate patterns, not a forecast for a particular trip.
December is a cool month in Porto: daytime highs average 13.5°C and nights cool to about 7.4°C. By daytime temperature it is the 11th warmest of the 12 months.
Expect about 167 mm of rain on roughly 12 days, which makes December a wet month (the wettest month of the year). Daylight, from sunrise to sunset, lasts about 9 h 16 min on an average December day.
The nearest other city in this atlas is Braga (47 km away). In December its highs average 12.5°C, 1.0°C cooler than Porto, with 205 mm of rain.
Among the 12 cities listed in Portugal, Porto ranks 10th of 12 for the warmest December highs and 11th of 12 for the driest December (rainfall, lowest first). The mean December high of those 12 cities is 14.4°C; Porto is 0.9°C cooler than that mean.
From December to January, average highs fall by 0.7°C to 12.8°C, and monthly rainfall falls from 167 mm to 150 mm.
The annual picture
December 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 | 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, selected | 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
December in nearby cities
- Braga in DecemberPortugal · 47 kmHigh 12.5°C · Low 4.8°C · 205 mm rain
- Aveiro in DecemberPortugal · 56 kmHigh 14.3°C · Low 7.6°C · 141 mm rain
- Viseu in DecemberPortugal · 80 kmHigh 11.1°C · Low 4.1°C · 160 mm rain
- Coimbra in DecemberPortugal · 106 kmHigh 14.3°C · Low 6.0°C · 111 mm rain
- Vigo in DecemberSpain · 121 kmHigh 13.1°C · Low 7.4°C · 224 mm rain
- Pontevedra in DecemberSpain · 143 kmHigh 13.4°C · Low 7.1°C · 198 mm rain
- Ourense in DecemberSpain · 146 kmHigh 12.2°C · Low 4.6°C · 114 mm rain
- Leiria in DecemberPortugal · 157 kmHigh 15.0°C · Low 8.2°C · 91 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.