Weather in Kingston in December

The month to avoid. December is the month most people should skip in Kingston. Highs sit at 2 °C and the day is short; this is an indoors-with-excursions month, not an outdoors-all-day one.

December ranks 11 of 12 — near the bottom of Kingston's year. September is the month that works, and the swing between the two is 64 points, which is a different holiday rather than a slightly better one.

This is persistent light rain rather than storms: 18 wet days but only 2 heavy ones. It rarely cancels anything outright, and it rarely fully clears either. A jacket beats an umbrella. Layers, and a genuinely waterproof outer — at 2 °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: 21 nights drop below freezing, so anything left outside stays frozen; the day barely swings — 4.9 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest December day reached 15.4 °C and the coldest night fell to -19.7 °C, and the wettest single day dropped 26 mm — roughly 30% of the month's rain in one day.

December is one of the reliable ones — rainfall has stayed between 57 mm and 132 mm across all twenty years, a narrow enough band that the 86 mm average is something you can plan against rather than merely quote.

Wind is light at 12.1 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 86%, which at 2 °C means damp rather than muggy — the kind of cold that gets into a coat and stays there.

How December sits in the year

The month is on the way down: 6 °C cooler than November, with January dropping another 3.3 °C. The first week and the last are not the same trip.

Daylight in December

December sits at the dark end of Kingston's year — 8.9 hours of daylight against 15.5 at midsummer, holding steady all month. Sightseeing days are genuinely shorter, and an itinerary built for summer will not fit.

An inland climate

With no coast nearby, the year swings a fair way — 31.6 °C between the warmest afternoons and the coldest nights, wider than any coastal city at this latitude would manage.

How busy it gets

Quiet. Few other visitors, cheaper rooms, and a real chance some seasonal operators are shut.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

December in Kingston versus nearby

If Kingston is one option among several, the nearby comparison is worth making. Ottawa is close enough to be a coin toss — 4.6 °C cooler, 4 days less rain. Peterborough is close enough to be a coin toss — 2.4 °C cooler, 7 days less rain.

So: December is a compromise. September is 62 points better and is what Kingston 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 Kingston

See all twelve months in Kingston, or where else to go in December.