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 |
The Next Grand Minimum 
One of the things which needs to be discussed in this regard is the balance between the northern extremities where growing seasons become economic and southerly extremities where cooling makes the region more suitable than before for crop growing.
I’ve never read a single article of this nature in newspapers or blogs.
Perhaps you or others would consider this issue, since from a global perspective, the issue is the overall global productivity, not where exactly the productivity is manifested at any particular time.
The implications of an LIA are a migration of peoples towards lower latitudes. What is perhaps of more interest is whether climate shifts cause desert regions to become wetter, more fertile and hence provide replacement agricultural areas for those lost to cold in the north.
I’ll be moving south soon. I’m the other type of environmental refuge. Who can afford $5/gal propane? I wonder if that was in the IPCC’s formula? The Russians didn’t punish people by sending them to someplace warm, they sent them to Siberia.
May be Dena can post the current price of Propane in Arizona.
It does not matter what the climate is 400 miles out into the Gulf of Mexico. What can be grown in the north will shift south. However what is currently grown in the south can not be grown in the Gulf of Mexico.
Great insight! I had not given it that much thought.
My son gave me a book, “Man and Climate” published by the department of agriculture in 1942.
Despite all this “global warming” I still can’t reliably put tomato plants out before memorial day in my part of Illinois. Things haven’t warmed to extend the growing season in >70 years.