Wisconsin frost dates: C
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Cable | May 20 | Oct 1 | 134 d | 4a |
| Cadott | May 1 | Oct 8 | 160 d | 4b |
| Caledonia | Apr 22 | Oct 26 | 187 d | 5b |
| Cambria | May 6 | Oct 2 | 149 d | 5a |
| Cambridge | Apr 29 | Oct 14 | 168 d | 5b |
| Cameron | May 8 | Oct 2 | 147 d | 4b |
| Camp Douglas | May 1 | Oct 3 | 155 d | 4b |
| Camp Lake | Apr 30 | Oct 15 | 168 d | 5b |
| Campbellsport | May 1 | Oct 12 | 164 d | 5a |
| Caroline | May 13 | Sep 30 | 140 d | 5a |
| Cascade | May 3 | Oct 10 | 160 d | 5b |
| Casco | May 1 | Oct 18 | 170 d | 5b |
| Cashton | Apr 27 | Oct 14 | 170 d | 5a |
| Cassville | Apr 21 | Oct 18 | 180 d | 5a |
| Cataract | May 9 | Oct 1 | 145 d | 4b |
| Catawba | May 23 | Sep 23 | 123 d | 4a |
| Cazenovia | May 12 | Sep 29 | 140 d | 5a |
| Cecil | May 9 | Oct 2 | 146 d | 5a |
| Cedar Grove | May 5 | Oct 12 | 160 d | 5b |
| Cedarburg | Apr 23 | Oct 24 | 184 d | 5b |
| Centuria | May 4 | Oct 8 | 157 d | 4b |
| Chaseburg | Apr 22 | Oct 17 | 178 d | 5a |
| Chetek | May 8 | Oct 2 | 147 d | 4b |
| Chili | May 5 | Oct 5 | 153 d | 4b |
| Chilton | May 1 | Oct 14 | 166 d | 5b |
| Chippewa Falls | May 8 | Oct 4 | 149 d | 4b |
| Clam Lake | May 16 | Sep 30 | 137 d | 4a |
| Clayton | May 5 | Oct 4 | 152 d | 4b |
| Clear Lake | May 5 | Oct 4 | 152 d | 4b |
| Cleveland | May 5 | Oct 8 | 156 d | 5b |
| Clinton | Apr 30 | Oct 10 | 163 d | 5b |
| Clintonville | May 4 | Oct 6 | 155 d | 5a |
| Clyman | Apr 28 | Oct 10 | 165 d | 5a |
| Cobb | May 3 | Oct 7 | 157 d | 5a |
| Cochrane | Apr 23 | Oct 16 | 176 d | 4b |
| Colby | May 13 | Sep 26 | 136 d | 4b |
| Coleman | May 9 | Oct 6 | 150 d | 5a |
| Colfax | May 9 | Oct 1 | 145 d | 4b |
| Colgate | Apr 30 | Oct 16 | 169 d | 5a |
| Collins | May 6 | Oct 6 | 153 d | 5b |
| Coloma | May 10 | Oct 3 | 146 d | 4b |
| Columbus | Apr 30 | Oct 9 | 162 d | 5a |
| Combined Locks | May 4 | Oct 6 | 155 d | 5b |
| Comstock | May 5 | Oct 4 | 152 d | 4b |
| Conover | May 25 | Sep 24 | 122 d | 4b |
| Conrath | May 27 | Sep 22 | 118 d | 4b |
| Coon Valley | Apr 27 | Oct 13 | 169 d | 5a |
| Cornell | May 5 | Oct 2 | 150 d | 4b |
| Cornucopia | May 23 | Oct 2 | 132 d | 4b |
| Cottage Grove | May 1 | Oct 10 | 162 d | 5b |
| Couderay | frost any month | 4a | ||
| Crandon | May 19 | Sep 29 | 133 d | 4b |
| Crivitz | May 26 | Sep 22 | 119 d | 4b |
| Cross Plains | Apr 28 | Oct 15 | 170 d | 5a |
| Cuba City | Apr 19 | Oct 21 | 185 d | 5a |
| Cudahy | Apr 19 | Oct 29 | 193 d | 6a |
| Cumberland | May 5 | Oct 4 | 152 d | 4b |
| Curtiss | May 13 | Sep 26 | 136 d | 4b |
| Cushing | May 19 | Sep 25 | 129 d | 4a |
| Custer | May 4 | Oct 7 | 156 d | 4b |