Minnesota frost dates: B
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Babbitt | May 28 | Sep 14 | 109 d | 3b |
| Backus | May 5 | Oct 5 | 153 d | 4a |
| Badger | May 6 | Oct 3 | 150 d | 3b |
| Bagley | May 15 | Sep 26 | 134 d | 3b |
| Balaton | May 2 | Oct 5 | 156 d | 5a |
| Barnesville | May 5 | Oct 3 | 151 d | 4a |
| Barnum | May 12 | Oct 2 | 143 d | 4a |
| Barrett | May 4 | Oct 1 | 150 d | 4b |
| Barry | May 9 | Sep 28 | 142 d | 4b |
| Battle Lake | May 5 | Oct 5 | 153 d | 4a |
| Baudette | May 14 | Sep 26 | 135 d | 3b |
| Baxter | May 8 | Sep 29 | 144 d | 4a |
| Bayport | Apr 22 | Oct 19 | 180 d | 5a |
| Beardsley | May 9 | Sep 28 | 142 d | 4b |
| Beaver Bay | May 15 | Oct 1 | 139 d | 4a |
| Beaver Creek | May 1 | Oct 4 | 156 d | 5a |
| Becker | May 7 | Sep 28 | 144 d | 4b |
| Bejou | May 7 | Sep 28 | 144 d | 4a |
| Belgrade | May 4 | Oct 4 | 153 d | 4b |
| Belle Plaine | May 2 | Oct 5 | 156 d | 4b |
| Bellingham | May 3 | Oct 2 | 152 d | 4b |
| Beltrami | May 11 | Sep 27 | 139 d | 4a |
| Belview | Apr 30 | Oct 10 | 163 d | 4b |
| Bemidji | May 17 | Sep 26 | 132 d | 3b |
| Bena | May 8 | Oct 1 | 146 d | 3b |
| Benedict | May 4 | Oct 7 | 156 d | 4a |
| Benson | May 4 | Oct 3 | 152 d | 4b |
| Bertha | May 10 | Sep 30 | 143 d | 4a |
| Bethel | May 1 | Oct 7 | 159 d | 4b |
| Big Falls | May 24 | Sep 20 | 119 d | 3b |
| Big Lake | May 4 | Oct 5 | 154 d | 4b |
| Bigelow | May 3 | Oct 4 | 154 d | 4b |
| Bigfork | May 14 | Oct 2 | 141 d | 3b |
| Bingham Lake | Apr 30 | Oct 10 | 163 d | 5a |
| Birchdale | May 14 | Sep 26 | 135 d | 3b |
| Bird Island | May 6 | Oct 1 | 148 d | 4b |
| Biwabik | frost any month | 3b | ||
| Blackduck | May 24 | Sep 17 | 116 d | 3b |
| Blomkest | Apr 30 | Oct 7 | 160 d | 4b |
| Blooming Prairie | May 5 | Oct 6 | 154 d | 5a |
| Blue Earth | Apr 27 | Oct 10 | 166 d | 5a |
| Bluffton | May 10 | Sep 30 | 143 d | 4a |
| Bock | May 8 | Oct 1 | 146 d | 4a |
| Borup | May 11 | Sep 27 | 139 d | 4a |
| Bovey | May 17 | Sep 24 | 130 d | 3b |
| Bowlus | May 10 | Sep 29 | 142 d | 4a |
| Bowstring | May 14 | Oct 2 | 141 d | 3b |
| Boyd | May 4 | Oct 1 | 150 d | 4b |
| Braham | May 2 | Oct 4 | 155 d | 4b |
| Brainerd | May 13 | Sep 27 | 137 d | 4a |
| Brandon | May 2 | Oct 8 | 159 d | 4b |
| Breckenridge | May 4 | Oct 3 | 152 d | 4a |
| Brewster | May 3 | Oct 4 | 154 d | 5a |
| Bricelyn | Apr 30 | Oct 6 | 159 d | 5a |
| Brimson | frost any month | 3b | ||
| Britt | May 12 | Oct 1 | 142 d | 3b |
| Brook Park | May 16 | Sep 24 | 131 d | 4a |
| Brooks | May 9 | Sep 30 | 144 d | 3b |
| Brookston | May 26 | Sep 23 | 120 d | 4a |
| Brooten | May 4 | Oct 4 | 153 d | 4b |
| Browerville | May 13 | Sep 27 | 137 d | 4a |
| Browns Valley | May 9 | Sep 28 | 142 d | 4b |
| Brownsdale | Apr 30 | Oct 5 | 158 d | 4b |
| Brownsville | Apr 22 | Oct 17 | 178 d | 5a |
| Brownton | Apr 30 | Oct 4 | 157 d | 4b |
| Bruno | May 18 | Sep 26 | 131 d | 4a |
| Buckman | May 10 | Sep 29 | 142 d | 4a |
| Buffalo | Apr 30 | Oct 9 | 162 d | 4b |
| Buffalo Lake | Apr 30 | Oct 4 | 157 d | 4b |
| Buhl | Jun 5 | Sep 8 | 95 d | 3b |
| Burnsville | Apr 27 | Oct 10 | 166 d | 5a |
| Burtrum | May 13 | Sep 27 | 137 d | 4b |
| Butterfield | Apr 30 | Oct 7 | 160 d | 5a |
| Byron | May 12 | Sep 28 | 139 d | 4b |