Tracking Killing Frosts in Spring and Fall
One of the indicators that we are living in a cooling world will be late spring killing frosts in June, according to an insightful fellow blogger. I have been looking for an easy way to track and display this information. So far, I have captured this information for Ohio towns across the state. There has been no killing frosts in June at any of these towns in modern history.
What is a killing frost, as opposed to just a light frost? The temperature has to get down to 28º F to kill corn and soybean plants. Temperatures above 28º F don’t kill the entire plant, but will damage the leaves and the upper stem, according to Brian Lang, who is an Iowa State University Extension Field Agronomist.
So, what we are looking for? We are looking for news reports of 28º F temperatures in June. I have set up a Google Alerts for killing frosts reports in the news for both the spring and fall. I am now looking for a data base that lists early fall freezes in Ohio and other states to be added to this data base.
The time between the last spring freeze and earliest fall freeze defines the growing season. The length of the growing season determines when plants are mature enough for harvest, and if they have obtained the necessary sugars and proteans need by the core products that these field crops support.
An early fall freeze can be as damaging as a late spring freeze. The number of days between the last Spring freeze and the first Fall freeze constitutes the growing season. Late spring freezes and early fall freezes can shorten a regions growing season, which can limit field crop productivity. That is why, it is important to track both spring and fall freezes.
City State Grow Season Last Frost First Freeze
| Chicago | IL | 187 | Apr. 20 | Oct. 24 |
| Springfield | IL | 182 | Apr. 13 | Oct. 13 |
| Indianapolis | IN | 181 | Apr. 17 | Oct. 16 |
| South Bend | IN | 175 | Apr. 26 | Oct. 19 |
| Atlantic | IA | 148 | May 2 | Sept. 28 |
| Cedar Rapids | IA | 163 | Apr. 25 | Oct. 6 |
| Topeka | KS | 174 | Apr. 19 | Oct. 11 |
| Lansing | MI | 145 | May 10 | Oct. 3 |
| Marquette | MI | 154 | May 11 | Oct. 13 |
| Duluth | MN | 124 | May 21 | Sept. 23 |
| Willmar | MN | 154 | Apr. 30 | Oct. 1 |
| Fort Peck | MT | 141 | May 8 | Sept. 26 |
| Helena | MT | 121 | May 19 | Sept. 18 |
| Blair | NE | 167 | Apr. 25 | Oct. 10 |
| North Platte | NE | 137 | May 9 | Sept. 24 |
| Akron | OH | 192 | Apr. 18 | Oct. 28 |
| Cincinnati | OH | 192 | Apr. 13 | Oct. 23 |
| Rapid City | SD | 140 | May 9 | Sept. 27 |
| Bismarck | ND | 129 | May 14 | Sept. 21 |
| Green Bay | WI | 150 | May 6 | Oct. 4 |
| Janesville | WI | 164 | Apr. 28 | Oct. 10 |
