The best time to visit Cornwall
Month-by-month climate averages for Cornwall, Ontario, so you can pick your dates on data rather than guesswork.
The most comfortable time to visit Cornwall 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.
Cornwall is warmest in July (highs near 27°C) and coldest in February (lows around -9°C), with roughly 1129 mm of precipitation across the year and August the wettest month. The sweet spot for most visitors is May, June, September and October. Expect overnight frost in January, February, March and December.
These are long-run averages. For the actual days you are travelling, check the live Cornwall forecast — and note how much the models agree, because that tells you how much to trust it.
Cornwall weather by month
what to expect in Cornwall through the yearHere is Cornwall'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 Cornwall by season.