Weather in New York City in January

The month to avoid. Of the twelve, January is the one to avoid. Highs sit at 3.5 °C and the day is short; this is an indoors-with-excursions month, not an outdoors-all-day one.

January ranks 11 of 12 — near the bottom of New York City's year. September is the month that works, and the swing between the two is 52 points, which is a different holiday rather than a slightly better one.

Rain on 9 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 3.5 °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: 19 nights fall below freezing; the day barely swings — 5 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest January day reached 15.8 °C and the coldest night fell to -13.5 °C, and the wettest single day dropped 71 mm — roughly 72% of the month's rain in one day.

January is moderately variable: 44 mm in the driest year against 192 mm in the wettest, around an average of 99 mm. Roughly two Januarys in three land near that average, and the third does something else entirely.

Wind sits around 18.5 km/h — a steady breeze rather than a nuisance, and welcome on the warmer days, and humidity runs at 82%, which at 3.5 °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: 6.9 °C in December, 3.5 here, 4.1 in February. Nothing about the timing within the month matters much.

Daylight in January

January sits at the dark end of New York City'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 9.1 °C in January — too cold to swim without a wetsuit. The sea peaks at 24.4 °C in August and bottoms out at 6.8 °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 New York City versus nearby

If New York City is one option among several, the nearby comparison is worth making. Philadelphia is close enough to be a coin toss — within a degree on temperature, the same number of rain days. Boston is close enough to be a coin toss — 2.7 °C cooler, the same number of rain days.

So: January is a compromise. September is 52 points better and is what New York City 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 New York City

See all twelve months in New York City, or where else to go in January.