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 31 | May 24 | May 22 | May 16 | May 13 | May 12 | May 7 |
| Fall frost on or before | August 25 | September 5 | September 6 | September 13 | September 17 | September 19 | September 27 |
| Frost-free period ≤ (days) | 91 | 107 | 111 | 116 | 122 | 125 | 135 |
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 22 – April 5 |
| Sow peas, spinach, lettuce and radish outdoors (frost-tolerant) | April 19 – May 3 |
| Plant potatoes and onion sets | May 3 – May 17 |
| Transplant tomatoes and peppers; sow beans, corn, squash and cucumbers | May 24 – June 7 |
| Last sowing of quick crops (radish, lettuce, spinach) | July 29 – August 13 |
| Harvest or cover frost-tender crops | September 5 – September 12 |
| Plant garlic and spring bulbs | September 12 – October 10 |
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 18:58 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.