Frost Dates for 64157 — Kansas City, Missouri

Half of springs at Smithville Lake, MO see their last 32°F night by April 18; only one in ten is past it by April 4, and one in ten still has one after May 3. Planting tender crops after April 25 leaves a 30% risk of a frost on them, after April 29 20%, and after May 3 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 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 23, 10 days before the 32°F one. The freeze-free season lasts 183 days in a typical year, shorter than at 85% of the 158 Missouri stations; it reaches 202 days one year in ten and falls short of 163 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 10 days longer, to about April 28, and return around October 10. Severe cold of 16°F or below comes every winter, usually between November 27 and March 6.

July is the warmest month at Smithville Lake, MO, averaging 87°F by day and 68°F at night; January is the coldest at 36°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 16% of years.

Warmth for growing adds up to 3,705 growing degree days a year (base 50°F), fewer than at 82% of the 158 Missouri stations. 35% of them (1,306) have built up by the end of June, and July adds the most, 838. Precipitation totals 40.3 inches a year, most in May (5.4") and least in January (1.2"); May to September bring 60% of it.

The nearest other station, Kearney 3E, MO, 9 miles northeast of Kansas City, has a last frost 1 day later (April 19), a first frost 3 days earlier (October 17), a season 2 days shorter.

The first measurable snow (0.1 inch or more) in Kansas City usually arrives around December 9, and the last of the season around February 23. Those are the middle dates across the winters of 1991–2020 at Smithville Lake, MO, 8.5 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 54 days after the last snow.

ZIP 64157 is 9 miles from Smithville Lake, MO, which stands at 904 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 5 other ZIP codes share the station; its figures are presented in full for 64155 (Kansas City). The 2023 USDA Plant Hardiness Zone Map lists ZIP 64157 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.