1981–2010 normals; ECCC quality code “C” (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 24 | May 15 | May 11 | May 7 | May 1 | April 28 | April 23 |
| Fall frost on or before | September 20 | September 27 | September 29 | October 2 | October 7 | October 8 | October 15 |
| Frost-free period ≤ (days) | 128 | 135 | 142 | 147 | 155 | 159 | 167 |
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 11 – March 25 |
| Sow peas, spinach, lettuce and radish outdoors (frost-tolerant) | April 8 – April 22 |
| Plant potatoes and onion sets | April 22 – May 6 |
| Transplant tomatoes and peppers; sow beans, corn, squash and cucumbers | May 13 – May 27 |
| Last sowing of quick crops (radish, lettuce, spinach) | August 21 – September 5 |
| Harvest or cover frost-tender crops | September 28 – October 5 |
| Plant garlic and spring bulbs | October 5 – November 2 |
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 19:12 UTC.
Data Source: Environment and Climate Change Canada Environment and Climate Change Canada Data Servers End-use Licence.
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