Frost Dates for 66509 — Mayetta, Kansas

Half of springs at Holton, KS see their last 32°F night by April 24; only one in ten is past it by April 10, and one in ten still has one after May 7. Planting tender crops after April 30 leaves a 30% risk of a frost on them, after May 3 20%, and after May 7 10%. The 13 days between the even-odds date and the one-in-ten date is narrower than at 65% of the 110 Kansas stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 14 in half of years, as early as September 29 one year in ten, and holds off past October 26 one year in ten. A hard freeze of 28°F follows 10 days later, around October 24; in spring the one-in-ten date for 28°F is April 28, 9 days before the 32°F one. The freeze-free season lasts 172 days in a typical year, shorter than at 87% of the 110 Kansas stations; it reaches 191 days one year in ten and falls short of 153 one year in ten. On average 131 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 9 days longer, to about May 3, and return around October 4. Severe cold of 16°F or below comes every winter, usually between November 22 and March 14.

July is the warmest month at Holton, KS, averaging 88°F by day and 66°F at night; January is the coldest at 37°F and 15°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 28% of years.

Warmth for growing adds up to 3,610 growing degree days a year (base 50°F), fewer than at 94% of the 110 Kansas stations. 35% of them (1,271) have built up by the end of June, and July adds the most, 831. Precipitation totals 37.5 inches a year, most in May (5.0") and least in January (0.8"); May to September bring 61% of it.

The nearest other station, Valley Falls 3 SW, KS, 15 miles east of Mayetta, has a last frost 14 days earlier (April 10), a first frost 15 days later (October 29), a season 27 days longer.

The first measurable snow (0.1 inch or more) in Mayetta usually arrives around December 7, and the last of the season around March 2. Those are the middle dates across the winters of 1991–2020 at Holton, KS, 8.3 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 53 days after the last snow.

ZIP 66509 is 8 miles from Holton, KS, which stands at 1,050 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 66436 (Holton). The 2023 USDA Plant Hardiness Zone Map lists ZIP 66509 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.