Weather in Hamilton in December

The month to avoid. December is the month most people should skip in Hamilton. Highs sit at 1.8 °C and the day is short; this is an indoors-with-excursions month, not an outdoors-all-day one.

December ranks 10 of 12 — near the bottom of Hamilton's year. September is the month that works, and the swing between the two is 61 points, which is a different holiday rather than a slightly better one.

Rain on 12 days, 1 of them heavy. Enough to need a plan B, not enough to need a plan around it. Layers, and a genuinely waterproof outer — at 1.8 °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: 27 nights drop below freezing, so anything left outside stays frozen. Across the twenty years measured, the hottest December day reached 17.6 °C and the coldest night fell to -23.2 °C.

December is statistically steady but not small: the year-to-year variation is modest in relative terms, yet the wettest December on record still delivered 91 mm against 28 mm in the driest. In a month this wet, even a tame spread is a lot of rain in absolute terms — the 55 mm average is a reasonable planning figure, not a promise.

Wind is light at 13 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 89%, which at 1.8 °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: 6.8 °C cooler than November, with January dropping another 3.1 °C. The first week and the last are not the same trip.

Daylight in December

December sits at the dark end of Hamilton's year — 9 hours of daylight against 15.4 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 — 39 °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 Hamilton versus nearby

If Hamilton is one option among several, the nearby comparison is worth making. Toronto is close enough to be a coin toss — within a degree on temperature, 3 days more rain. Buffalo is close enough to be a coin toss — within a degree on temperature, 4 days more rain.

So: December is a compromise. September is 58 points better and is what Hamilton 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 Hamilton

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