1981–2010 normals; ECCC quality code “A” (A = WMO “3 and 5 rule”; B ≥ 25 years; C ≥ 20 years; D ≥ 15 years of data). An average is not a guarantee: a late frost is still possible.
| 10% | 25% | 33% | 50% | 66% | 75% | 90% | |
|---|---|---|---|---|---|---|---|
| Spring frost (0 °C or lower) on or after | June 1 | May 22 | May 17 | May 9 | May 3 | April 26 | April 18 |
| Fall frost on or before | September 11 | September 19 | September 22 | October 1 | October 9 | October 11 | October 20 |
| Frost-free period ≤ (days) | 103 | 124 | 132 | 143 | 153 | 162 | 183 |
Example: the spring 10% column is the date after which a frost occurs in only one year in ten.
| Start tomatoes, peppers and eggplant indoors | March 8 – March 22 |
| Sow peas, spinach, lettuce and radish outdoors (frost-tolerant) | April 5 – April 19 |
| Plant potatoes and onion sets | April 19 – May 3 |
| Transplant tomatoes and peppers; sow beans, corn, squash and cucumbers | May 10 – May 24 |
| Last sowing of quick crops (radish, lettuce, spinach) | August 23 – September 7 |
| Harvest or cover frost-tender crops | September 30 – October 7 |
| Plant garlic and spring bulbs | October 7 – November 4 |
General gardening rules of thumb computed from this station's average last/first frost dates; they are not ECCC data. Adjust to local conditions and seed-packet instructions.
Environment and Climate Change Canada — Canadian Climate Normals 1981–2010 (station data, MSC Datamart) (30-year averages; not updated). Retrieved 2026-10-18 19:02 UTC.
Data Source: Environment and Climate Change Canada Environment and Climate Change Canada Data Servers End-use Licence.
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