Below is a chart showing Canada frost dates in the spring and fall for various Canadian cities. (Click here for the U.S. frost dates.) 

PLEASE NOTE: The reference source for Canadian frost dates is Environment Canada’s National Climate Services. The last time their data set was calculated was for the 1981 to 2010 Normals. Below are some dates for select cities. If your city is not listed, click here. 

Canadian Frost Dates

Dates below reflects normal averages for a light freeze (29° to 32°F, or -2° to 0°C); local weather and topography may cause considerable variations. The possibility of frost occurring after the spring dates and before the fall dates is 50 percent. The classification of freezing temperatures is usually based on their effect on plants. A light freeze kills only tender plants, with little destructive effect on other vegetation.

City Province Growing Season
(Length in Days) Last Frost
Spring First Frost
Fall Athabasca AB 112 May 21 Sept. 10 Calgary AB 107 May 26 Sept. 10 Edmonton AB 132 May 10 Sept. 19 Grande Prairie AB 120 May 16 Sept. 13 Lethbridge AB 123 May 18 Sept. 18 Medicine Hat AB 127 May 14 Sept. 18 Peace River AB 109 May 21 Sept. 7 Red Deer AB 108 May 24 Sept. 9 Abbotsford BC 186 Apr. 20 Oct. 23 Castlegar BC 159 May 1 Oct. 7 Chilliwack BC 204 Apr. 11 Nov. 1 Coombs BC 151 May 7 Oct. 5 Dawson Creek BC 90 June 4 Sept. 2 Kamloops BC 159 Apr. 30 Oct. 6 Kelowna BC 130 May 16 Sept. 23 Nanaimo BC 175 Apr. 26 Oct. 18 Prince George BC 93 May 31 Sept. 1 Prince Rupert BC 158 May 9 Oct. 14 Vancouver BC 229 Mar. 27 Nov. 11 Victoria BC 205 Apr. 14 Nov. 5 Brandon MB 115 May 22 Sept. 14 Lynn Lake MB 99 June 4 Sept. 11 The Pas MB 116 May 26 Sept. 19 Thompson MB 70 Jun. 14 Aug. 23 Winnipeg MB 121 May 24 Sept. 22 Bathurst NB 132 May 17 Sept. 26 Fredericton NB 128 May 17 Sept. 22 Miramichi NB 128 May 20 Sept. 25 Moncton NB 127 May 23 Sept. 27 Saint John NB 139 May 17 Oct. 3 Corner Brook NL 141 May 23 Oct. 11 Gander NL 130 June 3 Oct. 11 Grand Falls NL 117 June 4 Sept. 29 St. John’s NL 136 June 1 Oct. 15 Halifax NS 177 May 1 Oct. 25 Kentville NS 134 May 20 Oct. 1 Sydney NS 145 May 24 Oct. 16 Truro NS 115 May 30 Sept. 22 Yarmouth NS 177 Apr. 29 Oct. 23 Fort Simpson NT 91 May 27 Aug. 26 Norman Wells NT 100 May 27 Sept. 4 Yellowknife NT 113 May 28 Sept. 18 Barrie ON 158 May 5 Oct. 10 Brantford ON 162 May 1 Oct. 10 Hamilton ON 168 Apr. 28 Oct. 13 Kapuskasing ON 95 June 8 Sept. 11 Kingston ON 168 Apr. 26 Oct. 11 London ON 154 May 8 Oct. 9 Ottawa ON 148 May 7 Oct. 2 Owen Sound ON 163 May 5 Oct. 15 Peterborough ON 133 May 14 Sept. 24 Sudbury ON 133 May 17 Sept. 27 Timmins ON 94 June 7 Sept. 9 Toronto ON 158 May 4 Oct. 9 Wawa ON 104 June 5 Sept. 17 Windsor ON 186 Apr. 22 Oct. 25 Alberton PE 129 May 28 Oct. 4 Charlottetown PE 152 May 18 Oct. 17 Summerside PE 167 May 6 Oct. 20 Baie Comeau QC 114 May 26 Sept. 17 La Tuque QC 114 May 30 Sept. 21 Magog QC 142 May 14 Oct. 3 Montreal QC 163 Apr. 29 Oct. 9 Quebec QC 139 May 12 Sept. 28 Rimouski QC 146 May 15 Oct. 8 Roberval QC 124 May 23 Sept. 24 Thetford Mines QC 136 May 17 Sept. 30 Trois-Rivieres QC 131 May 18 Sept. 26 Moose Jaw SK 123 May 17 Sept. 17 North Battleford SK 119 May 21 Sept. 17 Prince Albert SK 101 June 1 Sept. 10 Regina SK 105 May 28 Sept. 10 Saskatoon SK 116 May 22 Sept. 15 Weyburn SK 118 May 20 Sept. 15 Yorkton SK 115 May 22 Sept. 14 Dawson YT 72 June 4 Aug. 15 Watson Lake YT 94 May 30 Sept. 1 Whitehorse YT 87 June 4 Aug. 30

For the link to more frost dates, please click here.

Source: 

Courtesy of Environment Canada