Porto weather in December
In December, Porto has daytime highs averaging 14 °C, nights around 7.5 °C, with 12 wet days, and a sea temperature of 14 °C. Figures are 1991–2020 climate normals.
- 13.6°C Average high
- 7.5°C Average low
- 12days Wet days
- 171mm Rainfall
- 14.3°C Sea temperature
- 9.2h Daylight
Daily temperatures through December
How December develops
Averages for the first, middle and last part of the month, from daily 1991–2020 normals. Chance of rain is the share of years in which that calendar day recorded more than 1 mm.
| Days | Avg high | Avg low | Chance of rain |
|---|---|---|---|
| 1–10 December | 13.9 °C | 7.8 °C | 36 % |
| 11–20 December | 13.6 °C | 7.5 °C | 39 % |
| 21–31 December | 13.3 °C | 7.2 °C | 43 % |
- Rain is most likely over days 21–31 of December (43 % of days) and least likely over days 1–10 (36 %).
What to expect
| Measure | Typical December | Share of the month |
|---|---|---|
| Days above 25 °C | 0 of 31 | 0 % |
| Days above 30 °C | 0 of 31 | 0 % |
| Days below 0 °C | 0.07 of 31 | 0 % |
| Days with more than 1 mm rain | 12 of 31 | 40 % |
Conditions in December
| Measure | Average |
|---|---|
| Mean temperature | 10 °C |
| Record high (1991–2020) | 20 °C |
| Record low (1991–2020) | -0.7 °C |
| Relative humidity | 83 % |
| Wind speed | 18 km/h |
| Cloud cover | 62 % |
Where Porto ranks in December
| Ranking | Position | Value |
|---|---|---|
| The warmest places in Europe in December | 26th of 50 | 14 °C |
| Places with the best weather in Europe in December | 37th of 50 | 57/100 |
| Warmest sea temperatures in Europe in December | 39th of 50 | 14 °C |
December compared with the months around it
| Month | Avg high | Rainfall | Cloud |
|---|---|---|---|
| January | 12.9 °C | 154 mm | 60 % |
| February | 13.9 °C | 103 mm | 55 % |
| October | 20.1 °C | 166 mm | 57 % |
| November | 15.7 °C | 166 mm | 60 % |
| December | 13.6 °C | 171 mm | 62 % |
See all twelve months for Porto
- December is the 11th warmest month here.
- It is the 12th driest month of the year.
- It ranks 12th for least cloud cover.
- Days last about 9.2 hours from sunrise to sunset.
- It rains on 12 of 31 days — 40 % of the month.
- Nights are about 6.1 °C cooler than the middle of the day.
- The hottest December day on record since 1991 reached 20 °C, 6.3 °C above the usual daytime high.
- Beach score: 7 / 100 — see how this is calculated.
QuestionsDecember in Porto, answered
How warm is Porto in December?
Daily highs average 14 °C and nights fall to about 7.5 °C, a spread of 6.1 °C between afternoon and dawn. That makes December the 10th warmest month of the year here.
Does it rain much in Porto in December?
December averages 171 mm of rain, spread over about 12 of the 31 days — 40 % of the month. Cloud cover averages 62 % of the sky.
Is the sea warm enough to swim in December?
The sea averages 14 °C off Porto in December. Most people find water below 20 °C bracing and above 25 °C comfortable for a long swim; this figure is a monthly surface average, so a sheltered bay on a still afternoon can be warmer.
How long are the days in December?
Porto averages 9.2 hours between sunrise and sunset in December. Day length is computed from latitude and date, so it is exact rather than modelled — but it says nothing about how much of that time is sunny.
Data sources and method
- ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
- Open-Meteo — Open-Meteo.com. CC BY 4.0
- NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
- GeoNames — GeoNames.org. CC BY 4.0
- Normal period
- 1991–2020
- Dataset version
- era5-1991-2020-scores1.1
- Last processed
Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: daylight hours, beach and comfort scores, monthly rankings, threshold day counts, chance of a wet day by date, ten-day averages within the month. Full formulas are on the methodology page.
Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.