Frost Dates for 64145 — Kansas City, Missouri

Half of springs at Olathe Johnson Co Exec Airport, KS see their last 32°F night by April 8; only one in ten is past it by March 23, and one in ten still has one after April 23. Planting tender crops after April 15 leaves a 30% risk of a frost on them, after April 18 20%, and after April 23 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 29 in half of years, as early as October 15 one year in ten, and holds off past November 11 one year in ten. A hard freeze of 28°F follows 8 days later, around November 6; in spring the one-in-ten date for 28°F is April 13, 10 days before the 32°F one. The freeze-free season lasts 204 days in a typical year, longer than at 79% of the 158 Missouri stations; it reaches 223 days one year in ten and falls short of 184 one year in ten. On average 101 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 18, and return around October 19. Severe cold of 16°F or below comes every winter, usually between December 5 and February 28.

July is the warmest month at Olathe Johnson Co Exec Airport, KS, averaging 88°F by day and 69°F at night; January is the coldest at 39°F and 21°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 74% of years.

Warmth for growing adds up to 4,035 growing degree days a year (base 50°F), fewer than at 51% of the 158 Missouri stations. 36% of them (1,465) have built up by the end of June, and July adds the most, 874. Precipitation totals 37.8 inches a year, most in May (5.4") and least in January (1.1"); May to September bring 60% of it.

The nearest other station, Olathe 3E, KS, 9 miles west of Kansas City, has a last frost 2 days later (April 10), the same first-frost date, a season 2 days shorter.

The first measurable snow (0.1 inch or more) in Kansas City usually arrives around November 30, and the last of the season around March 13. Those are the middle dates across the winters of 1991–2020 at Olathe 3E, KS, 8.8 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 26 days after the last snow.

ZIP 64145 is 8 miles from Olathe Johnson Co Exec Airport, KS, which stands at 1,070 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 8 other ZIP codes share the station; its figures are presented in full for 64012 (Belton). The 2023 USDA Plant Hardiness Zone Map lists ZIP 64145 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.