Minnesota weather: Our green-up begins
(FOX 9) - While the grass has certainly started to green up, much of our perennials, trees and shrubs are still dormant. The garden is still empty, the soil is still quite cool to the touch, and even our tulips haven't appeared in a lot of cases.
Well, that is about to change. Our much-anticipated green-up is about to get a swift kick into high gear.
For much of our vegetation to grow, soil temperatures need to be at or above about 50 degrees for the bulk of our day. While that is a gross generalization, it's a good approximation of the temps many plants will need to sprout, grow and flourish. Well, to have soil temps average over 50 degrees, our temps have to be there as well.
That hasn't been the case through much of April and the first couple of days of May, but a gradual warm-up the next few days should get temperatures warm enough to finally allow our plants to start thriving.
Our initial spring leaf-out has amazingly already come and gone for central and southern Minnesota. It certainly doesn't look like it, but it's the point when that first little perennial leaf has sprung through the soil, which happened in many of these areas just a few days ago.
The map above shows when and where areas across the U.S. have already experienced the first spring leaf out and compares those areas to average. For much of central and southern Minnesota, we are roughly three weeks behind what is considered average.
That would put parts of central Minnesota in the record category for the latest return interval. That means during the period of record, which is only about the last 40 years, the areas in deep purple have never leafed out this late.
For the rest of Minnesota, the return interval is still on the order of every 10 years or more. Compared to average, we are experiencing some of the latest spring blooms on record compared to much of the country. Even though it wasn't the coldest April on record, we finished the month in 14th place. It was the persistence of the cold that really took its toll.