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 28 | May 21 | May 20 | May 15 | May 11 | May 8 | May 4 |
| Fall frost on or before | September 22 | September 25 | September 26 | September 29 | October 8 | October 10 | October 23 |
| Frost-free period ≤ (days) | 123 | 130 | 131 | 139 | 144 | 155 | 161 |
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 21 – April 4 |
| Sow peas, spinach, lettuce and radish outdoors (frost-tolerant) | April 18 – May 2 |
| Plant potatoes and onion sets | May 2 – May 16 |
| Transplant tomatoes and peppers; sow beans, corn, squash and cucumbers | May 23 – June 6 |
| Last sowing of quick crops (radish, lettuce, spinach) | August 20 – September 4 |
| Harvest or cover frost-tender crops | September 27 – October 4 |
| Plant garlic and spring bulbs | October 4 – November 1 |
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 19:13 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.