Frost Dates for 64424 — Bethany, Missouri

Half of springs at Bethany, MO see their last 32°F night by April 16; only one in ten is past it by April 1, and one in ten still has one after May 3. Planting tender crops after April 23 leaves a 30% risk of a frost on them, after April 27 20%, and after May 3 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 22 in half of years, as early as October 6 one year in ten, and holds off past November 2 one year in ten. A hard freeze of 28°F follows 9 days later, around October 31; in spring the one-in-ten date for 28°F is April 21, 12 days before the 32°F one. The freeze-free season lasts 186 days in a typical year, shorter than at 77% of the 158 Missouri stations; it reaches 205 days one year in ten and falls short of 165 one year in ten. On average 132 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 29, and return around October 12. Severe cold of 16°F or below comes every winter, usually between November 26 and March 9.

July is the warmest month at Bethany, MO, averaging 87°F by day and 66°F at night; January is the coldest at 34°F and 16°F. A freezing night is all but certain in every month from November 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 13% of years.

Warmth for growing adds up to 3,530 growing degree days a year (base 50°F), fewer than at 92% of the 158 Missouri stations. 35% of them (1,227) have built up by the end of June, and July adds the most, 817. Precipitation totals 39.3 inches a year, most in May (5.5") and least in January (1.0"); May to September bring 61% of it.

The nearest other station, Albany, MO, 16 miles west of Bethany, has a last frost 1 day later (April 17), a first frost 1 day earlier (October 21), a season 1 day shorter.

The first measurable snow (0.1 inch or more) in Bethany usually arrives around December 7, and the last of the season around March 7. Those are the middle dates across the winters of 1991–2020 at Bethany, MO, 0.6 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 40 days after the last snow.

ZIP 64424 is under a mile from Bethany, MO, which stands at 949 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 64424 in zone 6a, the band where the coldest night of the year averaged -10 to -5°F (-23.3 to -20.6°C) over 1991–2020; a zone describes winter lows, not frost dates.