Weather on August 21 in Ottawa
Historical weather data for August 21 in Ottawa, Canada
Based on 56 years of data from OTTAWA CDA RCS
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 56 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 48% of August 21st dates historically, with the wettest August 21st recording 0.87" of rain. Temperatures on this date have remained relatively stable over the past several decades.
Temperatures on this date have remained relatively stable over the past several decades.
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) |
|---|---|---|---|
| 2026 | 24°C (76°F) | 12°C (53°F) | -- |
| 2025 | 27°C (80°F) | 11°C (51°F) | -- |
| 2024 | 20°C (68°F) | 11°C (52°F) | 3 mm |
| 2023 | 22°C (72°F) | 12°C (53°F) | 0 mm |
| 2022 | 27°C (80°F) | 18°C (64°F) | 1 mm |
| 2021 | 33°C (91°F) | 19°C (67°F) | 0 mm |
| 2020 | 23°C (74°F) | 17°C (62°F) | 0 mm |
| 2019 | 28°C (83°F) | 18°C (65°F) | 1 mm |
| 2018 | 24°C (75°F) | 16°C (60°F) | 14 mm |
| 2017 | 28°C (82°F) | 17°C (62°F) | 10 mm |
| 2016 | 24°C (76°F) | 14°C (57°F) | 17 mm |
| 2015 | 24°C (76°F) | 17°C (62°F) | 0 mm |
| 2014 | 24°C (75°F) | 18°C (64°F) | 15 mm |
| 2013 | 31°C (87°F) | 17°C (63°F) | 3 mm |
| 2012 | 24°C (75°F) | 12°C (54°F) | 0 mm |
| 2011 | 22°C (71°F) | 14°C (58°F) | 18 mm |
| 2010 | 18°C (65°F) | 11°C (51°F) | 2 mm |
| 2009 | 26°C (79°F) | 20°C (68°F) | 5 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) | 2 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) | 2 mm |
| 2001 | 27°C (80°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) | 7 mm |
| 1998 | 26°C (79°F) | 16°C (61°F) | 5 mm |
| 1997 | 18°C (65°F) | 14°C (57°F) | 22 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) | 0 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) | 4 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) | 2 mm |
| 1986 | 23°C (74°F) | 16°C (60°F) | 20 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) | 6 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) | 19 mm |
| 1976 | 32°C (89°F) | 18°C (64°F) | 0 mm |
| 1975 | 23°C (74°F) | 7°C (45°F) | 1 mm |
| 1974 | 32°C (89°F) | 14°C (57°F) | 0 mm |
| 1973 | 25°C (77°F) | 17°C (63°F) | 11 mm |
| 1972 | 27°C (80°F) | 12°C (53°F) | 0 mm |
| 1971 | 24°C (75°F) | 13°C (56°F) | 1 mm |