Weather in Naples in January

Shoulder season. January is shoulder season in Naples — cheaper, quieter, and a genuine gamble. Highs sit at 12.6 °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 Naples's year. May is the month that works, and the swing between the two is 31 points, which is a different holiday rather than a slightly better one.

Rain on 12 days, 3 of them heavy. Enough to need a plan B, not enough to need a plan around it. Layers, and a genuinely waterproof outer — at 12.6 °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 19.4 °C and the coldest night fell to -2.3 °C, and the wettest single day dropped 33 mm — roughly 38% of the month's rain in one day.

January is moderately variable: 6 mm in the driest year against 194 mm in the wettest, around an average of 88 mm. Roughly two Januarys in three land near that average, and the third does something else entirely.

Wind is light at 8 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 85%, which at 12.6 °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: 13.8 °C in December, 12.6 here, 13.1 in February. Nothing about the timing within the month matters much.

Daylight in January

January sits at the dark end of Naples's year — 9.5 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 15.1 °C in January — cold — a quick dip rather than a swim, and a wetsuit if you are in for longer. The sea peaks at 26.7 °C in August and bottoms out at 14.3 °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 Naples versus nearby

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

So: January is a compromise. May is 31 points better and is what Naples 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 Naples

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