Frost Dates for 63624 — Bismarck, Missouri

Half of springs at Farmington, MO see their last 32°F night by April 13; only one in ten is past it by March 28, and one in ten still has one after April 30. Planting tender crops after April 20 leaves a 30% risk of a frost on them, after April 24 20%, and after April 30 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 21 in half of years, as early as October 6 one year in ten, and holds off past November 1 one year in ten. A hard freeze of 28°F follows 11 days later, around November 1; in spring the one-in-ten date for 28°F is April 18, 12 days before the 32°F one. The freeze-free season lasts 191 days in a typical year, shorter than at 60% of the 158 Missouri stations; it reaches 211 days one year in ten and falls short of 169 one year in ten. On average 104 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 13 days longer, to about April 26, and return around October 12. Severe cold of 16°F or below comes every winter, usually between December 4 and March 2.

July is the warmest month at Farmington, MO, averaging 89°F by day and 67°F at night; January is the coldest at 43°F and 23°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 82% of years.

Warmth for growing adds up to 4,114 growing degree days a year (base 50°F), more than at 59% of the 158 Missouri stations. 37% of them (1,542) have built up by the end of June, and July adds the most, 859. Precipitation totals 45.4 inches a year, most in May (5.5") and least in January (2.6"); May to September bring 45% of it.

The nearest other station, Potosi 4 SW, MO, 15 miles northwest of Bismarck and 205 feet higher, has a last frost 2 days earlier (April 11), a first frost 7 days later (October 28), a season 7 days longer.

The first measurable snow (0.1 inch or more) in Bismarck usually arrives around December 20, and the last of the season around March 5. Those are the middle dates across the winters of 1991–2020 at Farmington, MO, 13.1 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 39 days after the last snow.

ZIP 63624 is 13 miles from Farmington, MO, which stands at 900 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 4 other ZIP codes share the station; its figures are presented in full for 63640 (Farmington). The 2023 USDA Plant Hardiness Zone Map lists ZIP 63624 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.