Weather on August 21 in Ottawa
Historical weather data for August 21 in Ottawa, Canada
Based on 55 years of data from OTTAWA CDA
About This Date
August 21st in Ottawa, Canada typically brings pleasant summer weather, with average highs around 25°C and lows near 14°C. Over 55 years of records, the warmest August 21st was in 2021 (26°C average), while the coldest was 1982 (11°C) — a 28°F range across recorded history. Rain or other precipitation has occurred on about 45% of August 21st dates historically, with the wettest August 21st recording 3.3" of rain. The last decade has been 1.4°F warmer on this date compared to 20-30 years ago.
The last decade has been 1.4°F warmer on this date compared to 20-30 years ago.
Planning for August 21st in Ottawa? Great weather for outdoor activities. Consider bringing rain gear or an umbrella.
Year by Year History
| Year | High | Low | Precip (mm) |
|---|---|---|---|
| 2025 | 27°C (80°F) | 11°C (51°F) | -- |
| 2024 | 20°C (68°F) | 11°C (52°F) | 8 mm |
| 2023 | 22°C (72°F) | 12°C (53°F) | 0 mm |
| 2022 | 27°C (80°F) | 18°C (64°F) | 3 mm |
| 2021 | 33°C (91°F) | 19°C (67°F) | 0 mm |
| 2020 | 23°C (74°F) | 16°C (60°F) | 2 mm |
| 2019 | 28°C (83°F) | 18°C (64°F) | 0 mm |
| 2018 | 24°C (75°F) | 15°C (59°F) | 84 mm |
| 2017 | 28°C (82°F) | 17°C (62°F) | 24 mm |
| 2016 | 24°C (76°F) | 21°C (69°F) | 28 mm |
| 2015 | 24°C (76°F) | 17°C (62°F) | 1 mm |
| 2014 | 24°C (75°F) | 18°C (64°F) | 38 mm |
| 2013 | 30°C (86°F) | 17°C (62°F) | 0 mm |
| 2012 | 24°C (75°F) | 12°C (54°F) | 0 mm |
| 2011 | 22°C (71°F) | 14°C (58°F) | 45 mm |
| 2010 | 18°C (65°F) | 11°C (51°F) | 5 mm |
| 2009 | 26°C (79°F) | 20°C (68°F) | 14 mm |
| 2008 | 27°C (81°F) | 10°C (50°F) | 0 mm |
| 2007 | 23°C (73°F) | 7°C (44°F) | 0 mm |
| 2006 | 24°C (76°F) | 13°C (55°F) | 0 mm |
| 2005 | 27°C (81°F) | 16°C (60°F) | 5 mm |
| 2004 | 20°C (68°F) | 12°C (53°F) | 0 mm |
| 2003 | 30°C (86°F) | 17°C (62°F) | 0 mm |
| 2002 | 27°C (81°F) | 10°C (50°F) | 0 mm |
| 2001 | 26°C (79°F) | 18°C (64°F) | 0 mm |
| 2000 | 23°C (74°F) | 11°C (52°F) | 0 mm |
| 1999 | 24°C (75°F) | 16°C (60°F) | 17 mm |
| 1998 | 26°C (79°F) | 16°C (61°F) | 12 mm |
| 1997 | 18°C (65°F) | 14°C (57°F) | 56 mm |
| 1996 | 27°C (81°F) | 21°C (70°F) | 0 mm |
| 1995 | 31°C (88°F) | 18°C (65°F) | 0 mm |
| 1994 | 25°C (77°F) | 18°C (65°F) | 1 mm |
| 1993 | 19°C (67°F) | 10°C (50°F) | 0 mm |
| 1992 | 25°C (77°F) | 7°C (45°F) | 0 mm |
| 1991 | 18°C (65°F) | 16°C (60°F) | 11 mm |
| 1990 | 24°C (75°F) | 12°C (53°F) | 0 mm |
| 1989 | 26°C (78°F) | 19°C (67°F) | 1 mm |
| 1988 | 17°C (62°F) | 12°C (53°F) | 0 mm |
| 1987 | 27°C (81°F) | 10°C (50°F) | 4 mm |
| 1986 | 23°C (74°F) | 16°C (60°F) | 51 mm |
| 1985 | 24°C (75°F) | 12°C (53°F) | 0 mm |
| 1984 | 27°C (80°F) | 9°C (48°F) | 0 mm |
| 1983 | 24°C (75°F) | 12°C (54°F) | 16 mm |
| 1982 | 16°C (60°F) | 6°C (43°F) | 0 mm |
| 1981 | 28°C (83°F) | 13°C (55°F) | 0 mm |
| 1980 | 26°C (78°F) | 14°C (57°F) | 0 mm |
| 1979 | 24°C (76°F) | 13°C (56°F) | 0 mm |
| 1978 | 24°C (76°F) | 10°C (50°F) | 0 mm |
| 1977 | 23°C (73°F) | 6°C (43°F) | 48 mm |
| 1976 | 32°C (89°F) | 18°C (64°F) | 0 mm |
| 1975 | 23°C (74°F) | 7°C (45°F) | 2 mm |
| 1974 | 32°C (89°F) | 14°C (57°F) | 0 mm |
| 1973 | 25°C (77°F) | 17°C (63°F) | 27 mm |
| 1972 | 27°C (80°F) | 12°C (53°F) | 0 mm |
| 1971 | 24°C (75°F) | 13°C (56°F) | 3 mm |