Hamilton weather in September
Long-run climate averages for Hamilton, Ontario in September, plus what the forecast models say for the days ahead.
In September, Hamilton averages 23°C by day and 14°C at night. The wettest month is usually July.
September in Hamilton averages a daytime high of 23°C and an overnight low of 14°C, which reads as warm for this part of the world. Across the whole year Hamilton sees roughly 1011 mm of precipitation.
Climate averages tell you what to pack. They do not tell you what next Tuesday looks like - for that, see the live Hamilton forecast with every model compared and how much they currently agree.
Hamilton weather by month
what to expect in Hamilton through the yearHere is Hamilton'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 Hamilton by season.
Bottom line: over the last 30 days the European model has been the most accurate forecast for Hamilton, scoring 94/100 on our CheckWeather Score, ahead of the American at 75. See the full CA accuracy scoreboard for exactly how every model is tested.
Common questions
How warm is Hamilton in September?
Is September a good time to visit Hamilton?
Does it rain a lot in Hamilton in September?
Climate averages from ERA5 reanalysis. Model accuracy re-scored over a rolling 30 days. Page updated .