Frost Charts for Canada and United States
Dates given are normal averages for a light freeze (32°F); 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, with the following commonly accepted categories:
Light freeze:
29°F to 32°F—tender plants killed, with little destructive effect on other vegetation.
Moderate freeze:
25°F to 28°F—widely destructive effect on most vegetation, with heavy damage to fruit blossoms and tender and semi-hardy plants.
Severe freeze:
24°
F and colder—damage to most plants.
City Province/State // Growing Season (Length in Days) // Last Spring Frost // First Fall Frost
Canada
Athabasca AB:
# of growing days 88 //
last spring frost Jun. 1 //
first fall frost Aug. 29
Calgary AB 114 May 23 Sept. 15
Edmonton AB 138 May 7 Sept. 23
Grande Prairie AB 117 May 18 Sept. 13
Lethbridge AB 123 May 17 Sept. 18
Medicine Hat AB 128 May 16 Sept. 22
Peace River AB 99 May 26 Sept. 3
Red Deer AB 106 May 25 Sept. 9
Abbotsford BC 177 Apr. 24 Oct. 18
Chilliwack BC 216 Apr. 6 Nov. 9
Dawson Creek BC 84 Jun. 5 Aug. 29
Kamloops BC 156 Jun. 1 Oct. 5
Kelowna BC 123 May 19 Sept. 20
Nanaimo BC 171 Apr. 28 Oct. 17
Nelson BC 159 May 4 Oct. 13
Port Alberni BC 159 May 8 Oct. 15
Prince George BC 91 Jun. 4 Sept. 3
Prince Rupert BC 156 May 9 Oct. 13
Vancouver BC 221 Mar. 28 Nov. 5
Victoria BC 200 Apr. 19 Nov. 5
Brandon MB 105 May 27 Sept. 10
Lynn Lake MB 89 Jun. 8 Sept. 6
The Pas MB 112 May 27 Sept. 17
Thompson MB 61 Jun. 15 Aug. 16
Winnipeg MB 119 May 25 Sept. 22
Bathurst NB 129 May 19 Sept. 26
Edmundston NB 112 May 28 Sept. 18
Fredericton NB 124 May 20 Sept. 22
Moncton NB 125 May 24 Sept. 27
Saint John NB 139 May 18 Oct. 4
Corner Brook NF 142 May 22 Oct. 12
Gander NF 123 Jun. 3 Oct. 5
Grand Falls NF 115 Jun. 2 Sept. 26
St. John's NF 131 Jun. 2 Oct. 12
Halifax NS 166 May 6 Oct. 20
Kentville NS 141 May 16 Oct. 5
Sydney NS 141 May 24 Oct. 13
Truro NS 113 May 30 Sept. 21
Yarmouth NS 169 May 1 Oct. 18
Aklavik NT 76 Jun. 13 Aug. 31
Fort Simpson NT 81 Jun. 3 Aug. 24
Yellowknife NT 110 May 27 Sept. 15
Barrie ON 112 May 26 Sept. 16
Hamilton ON 168 Apr. 29 Oct. 15
Kapuskasing ON 87 Jun. 12 Sept. 8
Kingston ON 160 May 2 Oct. 10
Kitchener ON 139 May 11 Sept. 29
London ON 151 May 9 Oct. 8
Ottawa ON 151 May 6 Oct. 5
Owen Sound ON 155 May 12 Oct. 15
Peterborough ON 124 May 18 Sept. 20
Sudbury ON 130 May 17 Sept. 25
Thunder Bay ON 105 Jun. 1 Sept. 15
Timmins ON 89 Jun. 8 Sept. 6
Toronto ON 149 May 9 Oct. 6
Windsor ON 179 Apr. 25 Oct. 22
Charlottetown PE 150 May 17 Oct. 14
Summerside PE 162 May 9 Oct. 19
Tignish PE 138 May 23 Oct. 9 Baie
Comeau QC 109 May 28 Sept. 15
Chicoutimi QC 133 May 17 Sept. 30
Montreal QC 156 May 3 Oct. 7
Quebec QC 139 May 13 Sept. 29
Rimouski QC 139 May 13 Sept. 30
Sherbrooke QC 100 Jun. 1 Sept. 10
Tadoussac QC 141 May 13 Oct. 2
Thetford Mines QC 106 May 28 Sept. 14
Trois-Rivieres QC 124 May 19 Sept. 23
Moose Jaw SK 120 May 20 Sept. 18
North Battleford SK 120 May 19 Sept. 17
Prince Albert SK 93 Jun. 2 Sept. 4
Regina SK 111 May 21 Sept. 10
Saskatoon SK 116 May 21 Sept. 15
Weyburn SK 112 May 22 Sept. 12
Yorkton SK 110 May 23 Sept. 11
Dawson YT 62 Jun. 13 Aug. 17
Watson Lake YT 91 Jun. 2 Sept. 4
US
Mobile AL:
272 //
Feb. 27 //
Nov. 26
Juneau AK 133 May 16 Sept. 26
Phoenix AZ 308 Feb. 5 Dec. 15
Tucson AZ 273 Feb. 28 Nov. 29
Pine Bluff AR 234 Mar. 19 Nov. 8
Eureka CA 324 Jan. 30 Dec. 15
Sacramento CA 289 Feb. 14 Dec. 1
San Francisco CA * * *
Denver CO 157 May 3 Oct. 8
Hartford CT 167 Apr. 25 Oct. 10
Wilmington DE 198 Apr. 13 Oct. 29
Miami FL * * *
Tampa FL 338 Jan. 28 Jan. 3
Athens GA 224 Mar. 28 Nov. 8
Savannah GA 250 Mar. 10 Nov. 15
Boise ID 153 May 8 Oct. 9
Chicago IL 187 Apr. 22 Oct. 26
Springfield IL 185 Apr. 17 Oct. 19
Indianapolis IN 180 Apr. 22 Oct. 20
South Bend IN 169 May 1 Oct. 18
Atlantic IA 141 May 9 Sept. 28
Cedar Rapids IA 161 Apr. 29 Oct. 7
Topeka KS 175 Apr. 21 Oct. 14
Lexington KY 190 Apr. 17 Oct. 25
Monroe LA 242 Mar. 9 Nov. 7
New Orleans LA 288 Feb. 20 Dec. 5
Portland ME 143 May 10 Sept. 30
Baltimore MD 231 Mar. 26 Nov. 13
Worcester MA 172 Apr. 27 Oct. 17
Lansing MI 140 May 13 Sept. 30
Marquette MI 159 May 12 Oct. 19
Duluth MN 122 May 21 Sept. 21
Willmar MN 152 May 4 Oct. 4
Columbus MS 215 Mar. 27 Oct. 29
Vicksburg MS 250 Mar. 13 Nov. 18
Jefferson City MO 173 Apr. 26 Oct. 16
Fort Peck MT 146 May 5 Sept. 28
Helena MT 122 May 18 Sept. 18
Blair NE 165 Apr. 27 Oct. 10
North Platte NE 136 May 11 Sept. 24
Las Vegas NV 259 Mar. 7 Nov. 21
Concord NH 121 May 23 Sept. 22
Newark NJ 219 Apr. 4 Nov. 10
Carlsbad NM 223 Mar. 29 Nov. 7
Los Alamos NM 157 May 8 Oct. 13
Albany NY 144 May 7 Sept. 29
Syracuse NY 170 Apr. 28 Oct. 16
Fayetteville NC 212 Apr. 2 Oct. 31
Bismarck ND 129 May 14 Sept. 20
Akron OH 168 May 3 Oct. 18
Cincinnati OH 195 Apr. 14 Oct. 27
Lawton OK 217 Apr. 1 Nov. 5
Tulsa OK 218 Mar. 30 Nov. 4
Pendleton OR 188 Apr. 15 Oct. 21
Portland OR 217 Apr. 3 Nov. 7
Carlisle PA 182 Apr. 20 Oct. 20
Williamsport PA 168 Apr. 29 Oct. 15
Kingston RI 144 May 8 Sept. 30
Charleston SC 253 Mar. 11 Nov. 20
Columbia SC 211 Apr. 4 Nov. 2
Rapid City SD 145 May 7 Sept. 29
Memphis TN 228 Mar. 23 Nov. 7
Nashville TN 207 Apr. 5 Oct. 29
Amarillo TX 197 Apr. 14 Oct. 29
Denton TX 231 Mar. 25 Nov. 12
San Antonio TX 265 Mar. 3 Nov. 24
Cedar City UT 134 May 20 Oct. 2
Spanish Fork UT 156 May 8 Oct. 12
Burlington VT 142 May 11 Oct. 1
Norfolk VA 239 Mar. 23 Nov. 17
Richmond VA 198 Apr. 10 Oct. 26
Seattle WA 232 Mar. 24 Nov. 11
Spokane WA 153 May 4 Oct. 5
Parkersburg WV 175 Apr. 25 Oct. 18
Green Bay WI 143 May 12 Oct. 2
Janesville WI 164 Apr. 28 Oct. 10
Casper WY 123 May 22 Sept. 22
*** Frosts do not occur every year. (Miami and San Francisco)
.