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 | May 20 | May 12 | May 10 | May 5 | April 30 | April 26 | April 18 |
| Fall frost on or before | September 18 | September 26 | September 28 | October 5 | October 9 | October 12 | October 19 |
| Frost-free period ≤ (days) | 131 | 140 | 143 | 150 | 155 | 159 | 175 |
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 4 – March 18 |
| Sow peas, spinach, lettuce and radish outdoors (frost-tolerant) | April 1 – April 15 |
| Plant potatoes and onion sets | April 15 – April 29 |
| Transplant tomatoes and peppers; sow beans, corn, squash and cucumbers | May 6 – May 20 |
| Last sowing of quick crops (radish, lettuce, spinach) | August 22 – September 6 |
| Harvest or cover frost-tender crops | September 29 – October 6 |
| Plant garlic and spring bulbs | October 6 – November 3 |
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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