Frost Dates for 63382 — Vandalia, Missouri

Half of springs at Vandalia, MO see their last 32°F night by April 11; only one in ten is past it by March 31, and one in ten still has one after April 25. Planting tender crops after April 18 leaves a 30% risk of a frost on them, after April 20 20%, and after April 25 10%. The 14 days between the even-odds date and the one-in-ten date is narrower than at 80% of the 158 Missouri stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 23 in half of years, as early as October 7 one year in ten, and holds off past November 3 one year in ten. A hard freeze of 28°F follows 9 days later, around November 1; in spring the one-in-ten date for 28°F is April 15, 10 days before the 32°F one. The freeze-free season lasts 192 days in a typical year, shorter than at 58% of the 158 Missouri stations; it reaches 211 days one year in ten and falls short of 173 one year in ten. On average 119 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 April 23, and return around October 14. Severe cold of 16°F or below comes every winter, usually between November 30 and March 5.

July is the warmest month at Vandalia, MO, averaging 86°F by day and 66°F at night; January is the coldest at 36°F and 19°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 87% of years.

Warmth for growing adds up to 3,693 growing degree days a year (base 50°F), fewer than at 83% of the 158 Missouri stations. 36% of them (1,324) have built up by the end of June, and July adds the most, 818. Precipitation totals 41.4 inches a year, most in June (5.1") and least in December (2.0"); May to September bring 53% of it.

The nearest other station, Bowling Green 1 E, MO, 17 miles east of Vandalia, has a last frost 2 days later (April 13), the same first-frost date, a season 4 days shorter.

The first measurable snow (0.1 inch or more) in Vandalia usually arrives around December 11, and the last of the season around March 11. Those are the middle dates across the winters of 1991–2020 at Vandalia, MO, 0.3 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 31 days after the last snow.

ZIP 63382 is under a mile from Vandalia, MO, which stands at 764 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 63361 (Montgomery City). The 2023 USDA Plant Hardiness Zone Map lists ZIP 63382 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.