EN · FR
☰✕
Ontario · climate station 6137362 · 209.1 m

St Thomas Wpcp

Average last spring frostMay 8
Average first fall frostOctober 8
Frost-free period152 days

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.

Probabilities

10%25%33%50%66%75%90%
Spring frost (0 °C or lower) on or afterMay 23May 17May 14May 8May 2April 29April 25
Fall frost on or beforeSeptember 23October 4October 4October 9October 14October 19October 26
Frost-free period ≤ (days)137146148152159161166

Example: the spring 10% column is the date after which a frost occurs in only one year in ten.

Indicative planting calendar

Start tomatoes, peppers and eggplant indoorsMarch 13 – March 27
Sow peas, spinach, lettuce and radish outdoors (frost-tolerant)April 10 – April 24
Plant potatoes and onion setsApril 24 – May 8
Transplant tomatoes and peppers; sow beans, corn, squash and cucumbersMay 15 – May 29
Last sowing of quick crops (radish, lettuce, spinach)August 24 – September 8
Harvest or cover frost-tender cropsOctober 1 – October 8
Plant garlic and spring bulbsOctober 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.

Nearby stations

London Int'l Airport · 164 dCulloden Easey · 155 dIlderton Bear Creek · 160 dFoldens · 166 dNew Glasgow · 163 dStratford Wwtp · 146 d
Sources & licences

Environment and Climate Change Canada — Canadian Climate Normals 1981–2010 (station data, MSC Datamart) (30-year averages; not updated). Retrieved 2026-10-18 19:10 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.

Independent. OpenCanadaData is an independent website. It is not affiliated with, endorsed by, or acting on behalf of the Government of Canada or any government body. Original data is available free of charge from the official sources linked on each page.