Frost Dates: First and last frost dates for Munising, MI
The charts on this page show the probabilities of receiving a certain temperature on a certain day. Some examples that might help:
- You have a small 20% chance of getting 32° by September 15.
- There is a 50% chance of being hit by a 32° frost starting around September 29
- You have a 80% chance of seeing 32° by October 12
- Said another way, you have a 1 in 5 chance at making it to that day without a 32° night.
Temperature | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
---|---|---|---|---|---|---|---|---|---|
First 16° | Nov 3 | Nov 9 | Nov 14 | Nov 17 | Nov 21 | Nov 25 | Nov 29 | Dec 3 | Dec 9 |
First 20° | Oct 24 | Oct 30 | Nov 3 | Nov 7 | Nov 10 | Nov 14 | Nov 17 | Nov 22 | Nov 28 |
First 24° | Oct 14 | Oct 20 | Oct 25 | Oct 29 | Nov 2 | Nov 6 | Nov 10 | Nov 15 | Nov 22 |
First 28° | Sep 26 | Oct 4 | Oct 9 | Oct 13 | Oct 17 | Oct 21 | Oct 26 | Oct 31 | Nov 7 |
First 32° | Sep 8 | Sep 15 | Sep 20 | Sep 25 | Sep 29 | Oct 3 | Oct 7 | Oct 12 | Oct 19 |
First 36° | Aug 21 | Aug 29 | Sep 5 | Sep 10 | Sep 15 | Sep 20 | Sep 25 | Oct 1 | Oct 10 |
What's a safe temperature for tender plants? When the nightly temperature falls, frost can form, even above 32°, because the air is colder high above the ground and the frost can form up there and then fall down onto your garden and do some damage, even if it's 36° on the ground. So many factors come into play, including wind, concrete, houses, trees and other structures, etc etc etc. Because of all this, you might want to consider 36° as "the danger zone".
In your average springtime, you have a 90% chance that there will be no 36° nights by July 5. In other words, you can pretty much count on being safe from frost by that day. But we want to get those tomatoes in the ground as soon as possible, right? We see that there's still an 80% chance of 36° on May 29, so we don't dare plant that early. We wait a few days and by June 13 we are at the 50/50 point. At this point, we are close and we can start watching the weather forecast. If the upcoming week's forecast doesn't show below 40°, then it's probably okay to risk planting out your plants.
Temperature | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
---|---|---|---|---|---|---|---|---|---|
Last 16° | Apr 22 | Apr 16 | Apr 12 | Apr 8 | Apr 5 | Apr 2 | Mar 29 | Mar 25 | Mar 19 |
Last 20° | May 6 | Apr 28 | Apr 22 | Apr 18 | Apr 13 | Apr 9 | Apr 4 | Mar 30 | Mar 22 |
Last 24° | May 15 | May 9 | May 5 | May 1 | Apr 28 | Apr 24 | Apr 21 | Apr 16 | Apr 10 |
Last 28° | May 30 | May 24 | May 19 | May 15 | May 12 | May 8 | May 4 | Apr 29 | Apr 23 |
Last 32° | Jun 18 | Jun 11 | Jun 6 | Jun 1 | May 28 | May 24 | May 19 | May 14 | May 7 |
Last 36° | Jul 5 | Jun 27 | Jun 22 | Jun 17 | Jun 13 | Jun 8 | Jun 3 | May 29 | May 21 |
Data is provided by the NOAA National Centers for Environmental Information.