Frost Dates for 64683 — Trenton, Missouri

Half of springs at Trenton, MO see their last 32°F night by April 16; only one in ten is past it by April 3, and one in ten still has one after April 29. Planting tender crops after April 21 leaves a 30% risk of a frost on them, after April 25 20%, and after April 29 10%. The 13 days between the even-odds date and the one-in-ten date is narrower than at 94% of the 158 Missouri stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 20 in half of years, as early as October 5 one year in ten, and holds off past November 1 one year in ten. A hard freeze of 28°F follows 9 days later, around October 29; in spring the one-in-ten date for 28°F is April 21, 8 days before the 32°F one. The freeze-free season lasts 184 days in a typical year, shorter than at 81% of the 158 Missouri stations; it reaches 204 days one year in ten and falls short of 165 one year in ten. On average 127 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 11 days longer, to about April 27, and return around October 11. Severe cold of 16°F or below comes every winter, usually between November 29 and March 9.

July is the warmest month at Trenton, MO, averaging 89°F by day and 67°F at night; January is the coldest at 35°F and 16°F. A freezing night is all but certain in every month from November to April (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month.

Warmth for growing adds up to 3,765 growing degree days a year (base 50°F), fewer than at 79% of the 158 Missouri stations. 36% of them (1,349) have built up by the end of June, and July adds the most, 863. Precipitation totals 40.1 inches a year, most in May (6.0") and least in January (1.1"); May to September bring 59% of it.

The nearest other station, Chillicothe 2S, MO, 21 miles south of Trenton, has a last frost 1 day earlier (April 15), a first frost 1 day later (October 21), a season 3 days longer.

The first measurable snow (0.1 inch or more) in Trenton usually arrives around December 7, and the last of the season around March 5. Those are the middle dates across the winters of 1991–2020 at Trenton, 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 42 days after the last snow.

ZIP 64683 is under a mile from Trenton, MO, which stands at 837 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 64683 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.