Ottawa Weather in October
In October, Ottawa averages a high of 13°C (55°F) and a low of 4°C (39°F), from 55 years of daily records (1971–2026).
13°C
Average high
55°F
4°C
Average low
39°F
30°C
Record high
87°F · October 3, 2023
-7°C
Record low
19°F · October 20, 1972
What October Is Like in Ottawa
- 6 of the 10 warmest Octobers on record in Ottawa have come since 2011.
- October in Ottawa has become 1.7°C (3.0°F) warmer on average: the 2011–2025 average against 1970–1989.
- The coldest October reading, -7°C (19°F) on October 20, 1972, has not been matched in 54 years.
- October 2025 was the 5th warmest October in 55 years of records, 2.4°C (4.3°F) above the long-run average.
At least 1 mm of rain falls on 34% of October days, and the month averages 84 mm in total.
Warmest: 2017 (17.2°C)Latest: 2025 (16.3°C)10-year averageLong-run average (13.0°C)
Look Up a Day in October
See the weather in Ottawa on any October date, year by year.
Source: NOAA GHCN-Daily, Ottawa Cda (1971–2023); Ottawa Cda Rcs (2000–2026). Averages cover 1971–2026. How we compute this