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Newfoundland and Labrador · climate station 8403506 · 140.5 m

St John's A

Average last spring frostMay 30
Average first fall frostOctober 17
Frost-free period139 days

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.

Probabilities

10%25%33%50%66%75%90%
Spring frost (0 °C or lower) on or afterJune 16June 9June 6June 1May 26May 23May 18
Fall frost on or beforeSeptember 28October 7October 9October 15October 18October 21October 26
Frost-free period ≤ (days)112123126137142146151

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 indoorsApril 4 – April 18
Sow peas, spinach, lettuce and radish outdoors (frost-tolerant)May 2 – May 16
Plant potatoes and onion setsMay 16 – May 30
Transplant tomatoes and peppers; sow beans, corn, squash and cucumbersJune 6 – June 20
Last sowing of quick crops (radish, lettuce, spinach)September 2 – September 17
Harvest or cover frost-tender cropsOctober 10 – October 17
Plant garlic and spring bulbsOctober 17 – November 14

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

Swift Current · 94 dLethbridge · 77 dBoat Harbour · 97 dWinterland · 141 dMusgrave Harbour · 123 dGander Int'l A · 136 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 19:06 UTC.
Data Source: Environment and Climate Change Canada Environment and Climate Change Canada Data Servers End-use Licence.

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