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Ontario · climate station 6153853 · 296.9 m

Janetville

Average last spring frostMay 22
Average first fall frostSeptember 21
Frost-free period121 days

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.

Probabilities

10%25%33%50%66%75%90%
Spring frost (0 °C or lower) on or afterJune 11May 29May 28May 22May 16May 9May 8
Fall frost on or beforeSeptember 2September 13September 15September 21September 28October 3October 8
Frost-free period ≤ (days)85108112126133136145

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 27 – April 10
Sow peas, spinach, lettuce and radish outdoors (frost-tolerant)April 24 – May 8
Plant potatoes and onion setsMay 8 – May 22
Transplant tomatoes and peppers; sow beans, corn, squash and cucumbersMay 29 – June 12
Last sowing of quick crops (radish, lettuce, spinach)August 7 – August 22
Harvest or cover frost-tender cropsSeptember 14 – September 21
Plant garlic and spring bulbsSeptember 21 – October 19

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

Lindsay Frost · 143 dPeterborough A · 132 dBowmanville Mostert · 141 dBurketon Mclaughlin · 155 dOshawa Wpcp · 168 dCobourg Stp · 158 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 19:11 UTC.
Data Source: Environment and Climate Change Canada Environment and Climate Change Canada Data Servers End-use Licence.

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