Frost Dates for 63645 — Fredericktown, Missouri

Half of springs at Fredericktown, MO see their last 32°F night by April 21; only one in ten is past it by April 8, and one in ten still has one after May 8. Planting tender crops after April 29 leaves a 30% risk of a frost on them, after May 3 20%, and after May 8 10%. The 17 days between the even-odds date and the one-in-ten date is wider than at 66% of the 158 Missouri stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 16 in half of years, as early as October 1 one year in ten, and holds off past October 28 one year in ten. A hard freeze of 28°F follows 10 days later, around October 26; in spring the one-in-ten date for 28°F is April 27, 11 days before the 32°F one. The freeze-free season lasts 174 days in a typical year, shorter than at 97% of the 158 Missouri stations; it reaches 194 days one year in ten and falls short of 155 one year in ten. On average 115 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 12 days longer, to about May 3, and return around October 6. Severe cold of 16°F or below comes every winter, usually between November 30 and March 6.

July is the warmest month at Fredericktown, MO, averaging 88°F by day and 65°F at night; January is the coldest at 42°F and 21°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 27% of years.

Warmth for growing adds up to 3,766 growing degree days a year (base 50°F), fewer than at 78% of the 158 Missouri stations. 37% of them (1,397) have built up by the end of June, and July adds the most, 814. Precipitation totals 46.4 inches a year, most in April (5.3") and least in February (2.8"); May to September bring 44% of it.

The nearest other station, Farmington, MO, 18 miles north of Fredericktown, has a last frost 8 days earlier (April 13), a first frost 5 days later (October 21), a season 17 days longer.

The first measurable snow (0.1 inch or more) in Fredericktown usually arrives around December 22, and the last of the season around February 26. Those are the middle dates across the winters of 1991–2020 at Fredericktown, MO, 1.8 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 54 days after the last snow.

ZIP 63645 is 2 miles from Fredericktown, MO, which stands at 760 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 63645 in zone 6b, the band where the coldest night of the year averaged -5 to 0°F (-20.6 to -17.8°C) over 1991–2020; a zone describes winter lows, not frost dates.