Partly cloudy,much the same tomorrow
Env. Canada, the European and the American model put Markham's high today between 19° and 24°, a 5° split. Tomorrow looks partly cloudy around 23°, with a 6% chance of rain.
Markham, Ontario. Below we compare what Env. Canada, European, American forecast for Markham right now and flag exactly where they disagree, then break down Markham's weather month by month and which forecast model has been most accurate here.
We grade every model against the weather that actually happened, so you can see which forecast model is most accurate in Canada before you trust any single number.
Here is Markham's typical weather in each month: the average daytime high and overnight low in °C, how each month feels, and the wettest month marked. Use it to plan any trip to Markham by season.
Markham runs from warm summers, with July highs near 27°C, to cold winters, when February lows sit around -6°C (a swing of about 33°C across the year). April is usually the wettest month, and Markham sees roughly 1059 mm of precipitation annually. Overnight lows stay below freezing across 4 months (January, February, March and December), so Markham sees regular winter snowfall.
The most comfortable time to visit Markham is usually May, June, August and September, when daytime highs sit in the pleasant 16-26°C range and the heaviest April rain is behind you.
The CheckWeather Score blends temperature, wind and rain accuracy — each measured against ERA5 (the recorded weather) over the last 30 days across 1302 cities. Lower error means a higher score. See which forecast model is most accurate in Canada, how we measure forecast accuracy, or which model each weather app uses.
Bottom line: over the last 30 days the European model has been the most accurate forecast for Markham, scoring 89/100 on our CheckWeather Score, ahead of the Env. Canada at 82. See the full CA accuracy scoreboard for exactly how every model is tested.
The models often agree on temperature and still split on rain — and rain is usually what decides whether a plan survives. A wide rain range means the shower is genuinely uncertain, not that the forecast is wrong.