Weather in Aveiro in January
Portugal · 20-year averages, January
Shoulder season. January sits in between. You will get good days and you will lose some. Highs sit at 13.8 °C and the day is short; this is an indoors-with-excursions month, not an outdoors-all-day one.
January ranks 12 of 12 — near the bottom of Aveiro's year. July is the month that works, and the swing between the two is 43 points, which is a different holiday rather than a slightly better one.
Rain on 13 days, 4 of them heavy. Enough to need a plan B, not enough to need a plan around it. Layers, and a genuinely waterproof outer — at 13.8 °C the difference between a good day and a miserable one is entirely down to what you are wearing.
What the averages hide
The averages here are honest — no hidden extremes worth planning around. Across the twenty years measured, the hottest January day reached 19.1 °C and the coldest night fell to -0.8 °C, and the wettest single day dropped 54 mm — roughly 43% of the month's rain in one day.
January is moderately variable: 8 mm in the driest year against 298 mm in the wettest, around an average of 126 mm. Roughly two Januarys in three land near that average, and the third does something else entirely.
Wind is light at 6.5 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 86%, which at 13.8 °C means damp rather than muggy — the kind of cold that gets into a coat and stays there.
How January sits in the year
Temperatures hold steady either side: 14.5 °C in December, 13.8 here, 14.5 in February. Nothing about the timing within the month matters much.
Daylight in January
January sits at the dark end of Aveiro's year — 9.6 hours of daylight against 15.1 at midsummer, gaining 0.7 hours across the month. Sightseeing days are genuinely shorter, and an itinerary built for summer will not fit.
Sea temperature
The sea sits at about 14.4 °C in January — cold — a quick dip rather than a swim, and a wetsuit if you are in for longer. The sea peaks at 18.5 °C in August and bottoms out at 13.7 °C — water lags the air by a month or two, which is why the best swimming often comes after the best weather.
How busy it gets
Off season. The genuine off season: cheapest by a distance, with the caveat that some tours and restaurants close entirely.
Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.
January in Aveiro versus nearby
If Aveiro is one option among several, the nearby comparison is worth making. Leiria is close enough to be a coin toss — within a degree on temperature, 1 day less rain. Braga is close enough to be a coin toss — within a degree on temperature, 1 day more rain.
So: January is a compromise. July is 43 points better and is what Aveiro is actually like at its best — worth moving the trip for if that is possible, and worth adjusting expectations for if it is not.
Every month in Aveiro
| Month | High °C | Low °C | Rain days | Rain mm | Humidity % | Daylight h | Sea °C | Score |
|---|---|---|---|---|---|---|---|---|
| January | 13.8 | 7.6 | 13 | 126 | 86 | 9.6 | 14.4 | 54 |
| February | 14.5 | 7.5 | 11 | 89 | 83 | 10.6 | 13.7 | 61 |
| March | 16.4 | 8.9 | 12 | 97 | 81 | 11.9 | 13.8 | 65 |
| April | 18.2 | 10.5 | 12 | 87 | 80 | 13.2 | 14.5 | 71 |
| May | 20.9 | 12.5 | 9 | 58 | 77 | 14.4 | 15.8 | 83 |
| June | 23.9 | 14.9 | 4 | 29 | 74 | 15.1 | 17.5 | 92 |
| July | 26 | 16 | 2 | 11 | 72 | 14.8 | 18.1 | 97 |
| August | 26.8 | 16.5 | 3 | 18 | 70 | 13.8 | 18.5 | 95 |
| September | 25.7 | 15.9 | 6 | 47 | 71 | 12.5 | 18.5 | 88 |
| October | 21.9 | 14 | 13 | 127 | 77 | 11.2 | 18 | 72 |
| November | 16.9 | 10.4 | 13 | 132 | 83 | 10 | 16.7 | 64 |
| December | 14.5 | 8.2 | 12 | 110 | 85 | 9.3 | 15.2 | 58 |
See all twelve months in Aveiro, or where else to go in January.
Planning the rest of the trip
- Flight time to Aveiro how long you are actually in the air
- Aveiro time zone and the difference from home
- Days until your trip count down to the departure date