Weather on September 20 in Ottawa
Historical weather data for September 20 in Ottawa, Canada
Based on 55 years of data from OTTAWA CDA RCS
About This Date
September 20th in Ottawa, Canada typically brings mild fall weather, with average highs around 20°C and lows near 9°C. Over 55 years of records, the warmest September 20th was in 2002 (24°C average), while the coldest was 1977 (7°C) — a 31°F range across recorded history. Rain or other precipitation has occurred on about 45% of September 20th dates historically, with the wettest September 20th recording 2.89" of rain. The last decade has been 3.7°F cooler on this date compared to 20-30 years ago.
The last decade has been 3.7°F cooler on this date compared to 20-30 years ago.
Planning for September 20th in Ottawa? Great weather for outdoor activities. Consider bringing rain gear or an umbrella.
Year by Year History
| Year | High | Low | Precip (mm) |
|---|---|---|---|
| 2025 | 18°C (65°F) | 3°C (38°F) | -- |
| 2024 | 28°C (82°F) | 13°C (56°F) | 0 mm |
| 2023 | 18°C (65°F) | 7°C (44°F) | 0 mm |
| 2022 | 16°C (61°F) | 12°C (54°F) | 0 mm |
| 2021 | 24°C (76°F) | 6°C (43°F) | 0 mm |
| 2020 | 15°C (59°F) | 2°C (36°F) | 0 mm |
| 2019 | 26°C (78°F) | 10°C (50°F) | 0 mm |
| 2018 | 18°C (64°F) | 7°C (45°F) | 34 mm |
| 2017 | 27°C (80°F) | 18°C (64°F) | 0 mm |
| 2016 | 26°C (79°F) | 16°C (60°F) | 0 mm |
| 2015 | 18°C (64°F) | 7°C (45°F) | 0 mm |
| 2014 | 23°C (73°F) | 4°C (40°F) | 18 mm |
| 2013 | 26°C (79°F) | 10°C (50°F) | 0 mm |
| 2012 | 20°C (68°F) | 3°C (38°F) | 6 mm |
| 2011 | 22°C (71°F) | 9°C (49°F) | 5 mm |
| 2010 | 18°C (64°F) | 4°C (40°F) | 0 mm |
| 2009 | 22°C (72°F) | 2°C (35°F) | 0 mm |
| 2008 | 23°C (74°F) | 8°C (46°F) | 1 mm |
| 2007 | 24°C (76°F) | 11°C (52°F) | 0 mm |
| 2006 | 16°C (60°F) | 7°C (44°F) | 2 mm |
| 2005 | 23°C (73°F) | 14°C (57°F) | 0 mm |
| 2004 | 18°C (65°F) | 4°C (40°F) | 1 mm |
| 2003 | 22°C (72°F) | 17°C (62°F) | 0 mm |
| 2002 | 28°C (83°F) | 21°C (69°F) | 0 mm |
| 2001 | 19°C (67°F) | 16°C (60°F) | 10 mm |
| 2000 | 27°C (80°F) | 13°C (55°F) | 10 mm |
| 1999 | 23°C (74°F) | 13°C (55°F) | 73 mm |
| 1998 | 22°C (71°F) | 14°C (58°F) | 0 mm |
| 1997 | 12°C (53°F) | 10°C (50°F) | 14 mm |
| 1996 | 22°C (72°F) | 11°C (52°F) | 0 mm |
| 1995 | 14°C (58°F) | 10°C (50°F) | 7 mm |
| 1994 | 26°C (78°F) | 9°C (49°F) | 0 mm |
| 1993 | 13°C (56°F) | 1°C (34°F) | 0 mm |
| 1992 | 18°C (65°F) | 8°C (46°F) | 0 mm |
| 1991 | 14°C (57°F) | 1°C (33°F) | 0 mm |
| 1990 | 16°C (61°F) | 9°C (49°F) | 0 mm |
| 1989 | 24°C (76°F) | 14°C (57°F) | 0 mm |
| 1988 | 26°C (78°F) | 15°C (59°F) | 18 mm |
| 1987 | 13°C (56°F) | 11°C (52°F) | 12 mm |
| 1986 | 14°C (57°F) | 9°C (49°F) | 0 mm |
| 1985 | 31°C (87°F) | 16°C (61°F) | 0 mm |
| 1984 | 23°C (74°F) | 12°C (54°F) | 3 mm |
| 1983 | 32°C (90°F) | 14°C (58°F) | 0 mm |
| 1982 | 18°C (65°F) | 4°C (40°F) | 6 mm |
| 1981 | 10°C (50°F) | 7°C (45°F) | 0 mm |
| 1980 | 22°C (72°F) | 9°C (48°F) | 1 mm |
| 1979 | 14°C (57°F) | 0°C (32°F) | 1 mm |
| 1978 | 20°C (68°F) | 7°C (44°F) | 7 mm |
| 1977 | 8°C (46°F) | 7°C (44°F) | 26 mm |
| 1976 | 11°C (52°F) | 9°C (49°F) | 67 mm |
| 1975 | 19°C (66°F) | 15°C (59°F) | 36 mm |
| 1974 | 21°C (69°F) | 12°C (54°F) | 1 mm |
| 1973 | 12°C (54°F) | 4°C (40°F) | 1 mm |
| 1972 | 18°C (64°F) | 5°C (41°F) | 0 mm |
| 1971 | 21°C (69°F) | 13°C (56°F) | 4 mm |