While we have had some chilly nights the last couple of weeks, the coldest air of the season is on its way and will bring most of us our first freeze of the season. While much of northern South Dakota has already experienced below freezing temperatures this month, southern and eastern parts of the KDLT viewing area have avoided the coldest air so far, but that changes as we move into Thursday morning.

The afternoon clouds that have lingered in eastern South Dakota will move out through the evening hours and should really be gone by midnight tonight. What that allows is for the air at the surface to mix up into the upper atmosphere resulting in cooler temperatures in the drier air at the surface. The drier the air, the lower the temperatures can be expected to fall, and with dew points expected to be into the low mid 20s overnight, that’s about where some spots could fall by early Thursday morning. The coldest temperatures are likely to be north of Highway 212, but we still will see the upper 20s in southeast South Dakota and even into parts of northwest Iowa. The last time Sioux Falls recorded a temperature in the 20s was April 12, 183 days ago! That is nearly six months to the date!

Freeze Warnings are in effect tonight starting at 1am CDT and will last until Thursday at 9am CDT. This includes all of southeastern South Dakota as well as the rest of the Tri-State including Minnesota & nearly all Iowa, as well as northeastern Nebraska. A Freeze Warning means sub-freezing temperatures are imminent or highly likely. These conditions will kill crops and other sensitive vegetation.

With the colder temperatures, we will definitely see some frost out there across the area, so if you park outside you’re likely going to need the window scraper to start the day. A tip to help clear that out for those who do park outside, either warm up the car a couple minutes before you leave. Or if you want to save some gas, a great trick at defrosting windows in the winter is to use an Isopropyl Alcohol solution. It is pretty simple to make, get a spray bottle and fill it 1/3 of the way with water, then fill the rest of the bottle with Isopropyl Alcohol. Mix it up and then spray away! Isopropyl Alcohol has a freezing point of -128°F, so it will never freeze during the winter, meaning you can keep the bottle in the car with you to help you out throughout the winter! NOTE: NEVER use plain warm/hot water on your windshield as that could lead to it breaking the glass.

Make sure you bring in any plants that you want to keep because they won’t make it through the night. Also, don’t forget that jacket as you head out to work on Thursday morning, because you’ll need it! This cold spell will only last a day with relief of the 70s back for the weekend, but until then stay warm!

Brandon Spinner
Chief Meteorologist
Twitter: @wxspinner89