Longueuil weather
Loading live data…Cloudy,rain likely tomorrow
Env. Canada, the European and the American model agree on a high near 17° in Longueuil today. Tomorrow looks rain around 17°, with a 84% chance of rain, and the models disagree, so treat it as uncertain.
CheckWeather.io on iPhoneFree. No ads, no account.Longueuil weather in numbers
measured normals and 10 years of recorded weatherLongueuil swings 38°C across the year, from 27°C highs in July to -11°C lows in February, and August is usually the wettest month in a year that brings about 1211 mm of precipitation. Over 10 years of recorded weather it averages 66 days a year at 25°C or above, 12 of them at 30°C or above, 143 frost nights, and rain on 142 days.
Day counts are from the ERA5 reanalysis for Longueuil’s grid square, 2016 to 2025, counted the same way for every city so the numbers compare. A reanalysis square is an area, not a weather station, so it is good for counting days and not for a single day’s record.
The weather map: all three models at once
Env. Canada, European, American side by side around Longueuil and nearby towns.Live rain radar →Longueuil hourly forecast: next 14 hours
consensus of the three modelsRain in the next 24 hours, model by model
each model's own hourly precipitation, side by sideLoading the three models…
Longueuil 10-day forecast, out to 14 days
where the models agree, and where they splitLongueuil, Quebec. Below we compare what Env. Canada, European, American forecast for Longueuil right now and flag exactly where they disagree, then break down Longueuil'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.
Longueuil weather by month
what to expect in Longueuil through the yearHere is Longueuil'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 Longueuil by season.
What Longueuil's weather is like through the year
Longueuil runs from warm summers, with July highs near 27°C, to cold winters, when February lows sit around -11°C (a swing of about 38°C across the year). August is usually the wettest month, and Longueuil sees roughly 1211 mm of precipitation annually. Overnight lows stay below freezing across 4 months (January, February, March and December), so Longueuil sees regular winter snowfall.
Best time to visit Longueuil
The most comfortable time to visit Longueuil is usually May, June, September and October, when daytime highs sit in the pleasant 16-26°C range and the heaviest August rain is behind you.
Which forecast is most accurate in Longueuil?
CheckWeather Score, graded against the weather that actually happened
The CheckWeather Score blends temperature, wind and rain accuracy, each measured against ERA5 (the recorded weather) over the last 30 days across 1304 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 Longueuil, scoring 92/100 on our CheckWeather Score, ahead of the Env. Canada at 76. See the full CA accuracy scoreboard for exactly how every model is tested.
What do you think of the forecasts?
your vote countsThe accuracy above is the measured record. This is your opinion: which forecast service do you trust most in Canada? Give each 1 to 5 stars.
One vote per service. Anonymous: we store no personal data, only a one-way hash of your connection for a day to stop double votes.
Where the models disagree
temperature and rain, judged separatelyThe 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.