Weather on May 21 in Ottawa
Historical weather data for May 21 in Ottawa, Canada
Based on 56 years of data from OTTAWA CDA
About This Date
May 21st in Ottawa, Canada typically brings pleasant spring weather, with average highs around 21°C and lows near 9°C. Over 56 years of records, the warmest May 21st was in 1975 (24°C average), while the coldest was 2008 (8°C) — a 29°F range across recorded history. Rain or other precipitation has occurred on about 34% of May 21st dates historically, with the wettest May 21st recording 1.42" of rain. The last decade has been 6.5°F warmer on this date compared to 20-30 years ago.
The last decade has been 6.5°F warmer on this date compared to 20-30 years ago.
Planning for May 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 | 16°C (61°F) | 4°C (40°F) | -- |
| 2025 | 14°C (58°F) | 3°C (37°F) | 0 mm |
| 2024 | 29°C (84°F) | 16°C (60°F) | 3 mm |
| 2023 | 22°C (72°F) | 11°C (52°F) | 1 mm |
| 2022 | 30°C (86°F) | 17°C (62°F) | 33 mm |
| 2021 | 32°C (89°F) | 17°C (62°F) | 0 mm |
| 2020 | 24°C (76°F) | 9°C (48°F) | 0 mm |
| 2019 | 18°C (64°F) | 7°C (45°F) | 0 mm |
| 2018 | 26°C (78°F) | 9°C (48°F) | 0 mm |
| 2017 | 17°C (63°F) | 9°C (48°F) | 36 mm |
| 2016 | 26°C (78°F) | 9°C (48°F) | 1 mm |
| 2015 | 21°C (69°F) | 8°C (46°F) | 0 mm |
| 2014 | 24°C (75°F) | 9°C (48°F) | 0 mm |
| 2013 | 18°C (64°F) | 14°C (57°F) | 35 mm |
| 2012 | 28°C (83°F) | 17°C (62°F) | 5 mm |
| 2011 | 26°C (78°F) | 13°C (55°F) | 0 mm |
| 2010 | 23°C (74°F) | 11°C (52°F) | 0 mm |
| 2009 | 29°C (84°F) | 10°C (50°F) | 0 mm |
| 2008 | 10°C (50°F) | 6°C (42°F) | 4 mm |
| 2007 | 18°C (64°F) | 4°C (39°F) | 0 mm |
| 2006 | 13°C (55°F) | 5°C (41°F) | 5 mm |
| 2005 | 15°C (59°F) | 7°C (45°F) | 5 mm |
| 2004 | 17°C (63°F) | 8°C (47°F) | 0 mm |
| 2003 | 16°C (61°F) | 6°C (42°F) | 0 mm |
| 2002 | 15°C (59°F) | 4°C (40°F) | 0 mm |
| 2001 | 25°C (77°F) | 12°C (54°F) | 0 mm |
| 2000 | 18°C (64°F) | 5°C (41°F) | 0 mm |
| 1999 | 23°C (73°F) | 5°C (41°F) | 0 mm |
| 1998 | 14°C (57°F) | 9°C (49°F) | 0 mm |
| 1997 | 14°C (58°F) | 6°C (42°F) | 5 mm |
| 1996 | 23°C (74°F) | 16°C (61°F) | 0 mm |
| 1995 | 22°C (72°F) | 9°C (48°F) | 7 mm |
| 1994 | 26°C (79°F) | 11°C (51°F) | 0 mm |
| 1993 | 19°C (66°F) | 7°C (45°F) | 0 mm |
| 1992 | 29°C (85°F) | 13°C (55°F) | 0 mm |
| 1991 | 28°C (82°F) | 9°C (48°F) | 0 mm |
| 1990 | 15°C (59°F) | 7°C (44°F) | 0 mm |
| 1989 | 20°C (68°F) | 14°C (58°F) | 5 mm |
| 1988 | 22°C (71°F) | 12°C (54°F) | 0 mm |
| 1987 | 21°C (69°F) | 11°C (52°F) | 16 mm |
| 1986 | 16°C (60°F) | 11°C (51°F) | 13 mm |
| 1985 | 19°C (66°F) | 8°C (46°F) | 0 mm |
| 1984 | 19°C (66°F) | 6°C (42°F) | 0 mm |
| 1983 | 17°C (63°F) | 8°C (46°F) | 0 mm |
| 1982 | 18°C (64°F) | 7°C (45°F) | 0 mm |
| 1981 | 24°C (75°F) | 9°C (48°F) | 0 mm |
| 1980 | 26°C (79°F) | 8°C (46°F) | 0 mm |
| 1979 | 18°C (64°F) | 12°C (53°F) | 35 mm |
| 1978 | 20°C (68°F) | 8°C (46°F) | 0 mm |
| 1977 | 32°C (89°F) | 14°C (57°F) | 0 mm |
| 1976 | 14°C (58°F) | 7°C (45°F) | 7 mm |
| 1975 | 31°C (87°F) | 17°C (63°F) | 21 mm |
| 1974 | 18°C (64°F) | 9°C (48°F) | 0 mm |
| 1973 | 18°C (65°F) | 11°C (51°F) | 1 mm |
| 1972 | 26°C (78°F) | 13°C (55°F) | 0 mm |
| 1971 | 19°C (66°F) | 10°C (50°F) | 0 mm |