Ottawa Weather in August
In August, Ottawa averages a high of 26°C (78°F) and a low of 14°C (58°F), based on 55 years of historical weather data from OTTAWA CDA.
26°C
Average high
78°F
14°C
Average low
58°F
37°C
Record high
99°F · 2001
3°C
Record low
37°F · 1976
What to Expect in Ottawa in August
Typical August days in Ottawa reach 26°C (78°F) during the afternoon and cool to around 14°C (58°F) overnight. On average, measurable rain falls on about 37% of days this month. Over the past 55 years, August temperatures in Ottawa have ranged from a record high of 37°C (2001) down to a record low of 3°C (1976).
For a day-by-day look or other months, see the full Ottawa weather history.