1981–2010 normals; ECCC quality code “D” (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 19 | May 12 | May 10 | April 30 | April 21 | April 21 | April 17 |
| Fall frost on or before | September 20 | September 26 | September 29 | October 9 | October 11 | October 12 | October 24 |
| Frost-free period ≤ (days) | 133 | 144 | 149 | 159 | 163 | 172 | 188 |
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 6 – March 20 |
| Sow peas, spinach, lettuce and radish outdoors (frost-tolerant) | April 3 – April 17 |
| Plant potatoes and onion sets | April 17 – May 1 |
| Transplant tomatoes and peppers; sow beans, corn, squash and cucumbers | May 8 – May 22 |
| 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 19:00 UTC.
Data Source: Environment and Climate Change Canada Environment and Climate Change Canada Data Servers End-use Licence.
OpenCanadaData is independent and is not affiliated with or endorsed by these data publishers. Always check with the official source before you go.