Frost Dates for 63851 — Hayti, Missouri

Half of springs at Caruthersville, MO see their last 32°F night by March 24; only one in ten is past it by March 7, and one in ten still has one after April 8. Planting tender crops after March 31 leaves a 30% risk of a frost on them, after April 3 20%, and after April 8 10%. The 15 days between the even-odds date and the one-in-ten date is narrower than at 54% of the 158 Missouri stations behind this site's ZIP pages.

In fall the first 32°F night comes by November 9 in half of years, as early as October 26 one year in ten, and holds off past December 1 one year in ten. A hard freeze of 28°F follows 13 days later, around November 22; in spring the one-in-ten date for 28°F is March 28, 11 days before the 32°F one. The freeze-free season lasts 230 days in a typical year, the longest of the 158 Missouri stations; it reaches 255 days one year in ten and falls short of 207 one year in ten. On average 71 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 10 days longer, to about April 3, and return around October 29. Nights of 24°F, cold enough to damage hardier plants, come in 100% of winters and 16°F in 89%.

July is the warmest month at Caruthersville, MO, averaging 90°F by day and 72°F at night; January is the coldest at 46°F and 30°F. A freezing night is all but certain in every month from December 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 28% of years.

Warmth for growing adds up to 5,035 growing degree days a year (base 50°F), more than at 99% of the 158 Missouri stations. 39% of them (1,950) have built up by the end of June, and July adds the most, 965. Precipitation totals 55.3 inches a year, most in April (6.1") and least in August (3.1"); May to September bring 38% of it.

The nearest other station, Portageville, MO, 13 miles north of Hayti, has a last frost 1 day later (March 25), a first frost 2 days earlier (November 7), a season 3 days shorter.

The first measurable snow (0.1 inch or more) in Hayti usually arrives around December 23, and the last of the season around February 9. Those are the middle dates across the winters of 1991–2020 at Portageville, MO, 12.6 miles away: half of years saw snow earlier, half later. Snow fell in 95% of those winters. The last 32°F night of spring typically comes 43 days after the last snow.

ZIP 63851 is 6 miles from Caruthersville, MO, which stands at 270 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station; its figures are presented in full for 63830 (Caruthersville). The 2023 USDA Plant Hardiness Zone Map lists ZIP 63851 in zone 7b, the band where the coldest night of the year averaged 5 to 10°F (-15.0 to -12.2°C) over 1991–2020; a zone describes winter lows, not frost dates.