Average first freeze October 10-15

The coldest air of the season is heading for Mid-Missouri, as a cold front with Pacific origins arrives through Wednesday afternoon. This front will plummet our temperatures 20 to 30 degrees, as high will only be sitting in the upper 50s Thursday and overnight lows in the mid to upper 30s. The last time Mid-Missouri saw lows in the 30s was April 13th of this year, so it’s been nearly 6 months since we’ve seen temperatures that cold.

The cooler weather doesn’t come as a surprise as we are in the transition period where warm gulf air and cold arctic air begin to battle. The front tracking through Wednesday afternoon will bring some showers and storms, with a marginal risk of severe weather south of I-70. By late Wednesday evening the front and the rain will have tracked out of the area and this will set up the cold air to filter in.

Here in Mid-Missouri, the temperatures are expected to plummet into the 30s Wednesday night into Thursday morning. This will pose a threat in the form of some patchy frost, across some low lying areas. Although ABC17’s forecast only calls for a low of 38, patchy frost is still possible.

You may ask yourself how frost can form when the temperature is above freezing. Well, it all depends on thermometer placement. The official temperature comes from thermometers placed 4-6 feet above the ground in the shade. The reason this is done is because cold or hot air that has pooled near the ground can provide false readings on the radar.

During the cold fall/winter nights when the thermometer is 35-38 degrees, cold air can pool at the surface and be several degrees cooler. This is how patchy frost is possible even though the official temperature is above freezing.

With patchy frost in the forecast, now is the time to make preparations for sensitive plants and vegetation. It’s advised that you cover your plants with a polyester or cotton sheet. This will prevent the cold air from freezing the moisture on the plants and keeps the plants warm through the overnight hours.

You don’t need to bring the plants in, as the return of the 80s for highs and overnight lows in the 50s and 60s will swiftly return.