Frost Dates for 64648 — Jamesport, Missouri

Half of springs at Gallatin 1W, MO see their last 32°F night by April 19; only one in ten is past it by April 5, and one in ten still has one after May 4. Planting tender crops after April 27 leaves a 30% risk of a frost on them, after April 30 20%, and after May 4 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 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 9 days later, around October 30; in spring the one-in-ten date for 28°F is April 23, 11 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 202 days one year in ten and falls short of 162 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 30, and return around October 9. Severe cold of 16°F or below comes every winter, usually between November 28 and March 10.

July is the warmest month at Gallatin 1W, MO, averaging 86°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 18% of years.

Warmth for growing adds up to 3,461 growing degree days a year (base 50°F), fewer than at 96% of the 158 Missouri stations. 36% of them (1,233) have built up by the end of June, and July adds the most, 798. Precipitation totals 40.7 inches a year, most in May (5.6") and least in January (1.4"); May to September bring 60% of it.

The nearest other station, Trenton, MO, 13 miles northeast of Jamesport, has a last frost 3 days earlier (April 16), a first frost 1 day earlier (October 20).

The first measurable snow (0.1 inch or more) in Jamesport 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 Gallatin 1W, MO, 9.9 miles away: half of years saw snow earlier, half later. Snow fell in 93% of those winters. The last 32°F night of spring typically comes 45 days after the last snow.

ZIP 64648 is 10 miles from Gallatin 1W, MO, which stands at 921 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station; its figures are presented in full for 64640 (Gallatin). The 2023 USDA Plant Hardiness Zone Map lists ZIP 64648 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.