September comes with many attributes such as the green, summer leaves beginning to fade and the pumpkin spice lattes making their yearly debut. Meteorologically speaking, September tends to also bring the first frost for North Dakota.
Now there’s a difference between the first frost, a moderate frost, and a hard freeze. General knowledge supplies that freezing point is 32˚F, so when Mother Nature brings the air temperature down to that magic number, it is technically the first freeze. However, a moderate frost can be classified as any temperature between 32˚F and 28˚F; and we begin to hear the words “hard freeze” when the temperatures plummet below 28˚F.
Based on yearly data from 1981 to 2010, the freezing temperatures will begin to punch the clock mid-September to early October. The University of North Dakota, on average, will first see 32˚ on September 16th (which happens to be tomorrow… bundle up), a moderate frost on September 30th, and that hard freeze 28˚ mark on October 8th.
For the state of North Dakota, mind you that we’re an agriculture based state, the first freeze is more than just grabbing a jacket on the way to work. Depending on when that first freeze hits, farmers will either be cussing the temperature or praising it. Once crops such as corn, sunflowers, and soybeans are mature, they are ready for a hard freeze to “seal the deal” and be harvested. However, if the first freeze comes too early and the seeds aren’t mature enough, the freeze will hurt the crop, damage the grain, and decrease the yield.
Pictured above are frost damaged soybeans.
For now, we’ll keep letting the sun shine and mature the crops while we race to the nearest PSL. We’ll bundle up and watch the temperature drop to 32 while meteorologists take bets on which day the magic number will appear. We’ll deal with the first freeze, but we won’t worry, because as North Dakotans, we know that it’s only going to get colder.
Written by: Lydia Blume, an Atmospheric Sciences Student at the University of North Dakota
Interviews with Jon Stabler, a Crop and Weed Science major at North Dakota State University and Brayden Hofer, an Agriculture Econ major with a Crop and Weed minor at North Dakota State University.
Soybean picture: https://blogs.ext.vt.edu/soybean-update/2013/11/01/management-recommendations-for-frost-damaged-soybean/