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 28 | May 21 | May 18 | May 13 | May 10 | May 7 | April 29 |
| Fall frost on or before | September 21 | September 28 | October 1 | October 8 | October 10 | October 16 | October 23 |
| Frost-free period ≤ (days) | 122 | 133 | 135 | 146 | 154 | 158 | 166 |
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 17 – March 31 |
| Sow peas, spinach, lettuce and radish outdoors (frost-tolerant) | April 14 – April 28 |
| Plant potatoes and onion sets | April 28 – May 12 |
| Transplant tomatoes and peppers; sow beans, corn, squash and cucumbers | May 19 – June 2 |
| Last sowing of quick crops (radish, lettuce, spinach) | August 24 – September 8 |
| Harvest or cover frost-tender crops | October 1 – October 8 |
| Plant garlic and spring bulbs | October 8 – November 5 |
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 19:09 UTC.
Data Source: Environment and Climate Change Canada Environment and Climate Change Canada Data Servers End-use Licence.
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