The best time to visit Ottawa South
Month-by-month climate averages for Ottawa South, Ontario, so you can pick your dates on data rather than guesswork.
The most comfortable time to visit Ottawa South is usually May, June, August and September, when daytime highs sit in the pleasant 16-26°C range and the heaviest July rain is behind you.
Ottawa South is warmest in July (highs near 27°C) and coldest in February (lows around -11°C), with roughly 1155 mm of precipitation across the year and July the wettest month. The sweet spot for most visitors is May, June, August and September. Expect overnight frost in January, February, March and December.
These are long-run averages. For the actual days you are travelling, check the live Ottawa South forecast — and note how much the models agree, because that tells you how much to trust it.
Ottawa South weather by month
what to expect in Ottawa South through the yearHere is Ottawa South'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 Ottawa South by season.