Weather in Lisbon in January

Shoulder season. January is shoulder season in Lisbon — cheaper, quieter, and a genuine gamble. Highs sit at 14.4 °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 Lisbon's year. July is the month that works, and the swing between the two is 35 points, which is a different holiday rather than a slightly better one.

Rain on 10 days, 2 of them heavy. Enough to need a plan B, not enough to need a plan around it. Layers, and a genuinely waterproof outer — at 14.4 °C the difference between a good day and a miserable one is entirely down to what you are wearing.

What the averages hide

Averages flatten a month, and this one hides a few things: the day barely swings — 3.4 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest January day reached 17.8 °C and the coldest night fell to 4.4 °C, and the wettest single day dropped 31 mm — roughly 48% of the month's rain in one day.

January is moderately variable: 1 mm in the driest year against 145 mm in the wettest, around an average of 65 mm. Roughly two Januarys in three land near that average, and the third does something else entirely.

Wind sits around 17.4 km/h — a steady breeze rather than a nuisance, and welcome on the warmer days, and humidity runs at 81%, which at 14.4 °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: 15.1 °C in December, 14.4 here, 14.5 in February. Nothing about the timing within the month matters much.

Daylight in January

January sits at the dark end of Lisbon's year — 9.7 hours of daylight against 14.9 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 16 °C in January — cold — a quick dip rather than a swim, and a wetsuit if you are in for longer. The sea peaks at 20.7 °C in September and bottoms out at 15.3 °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 Lisbon versus nearby

If Lisbon is one option among several, the nearby comparison is worth making. Évora is close enough to be a coin toss — within a degree on temperature, 1 day less rain. Leiria is close enough to be a coin toss — within a degree on temperature, 2 days more rain.

So: January is a compromise. July is 35 points better and is what Lisbon 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 Lisbon

See all twelve months in Lisbon, or where else to go in January.