Frost Dates for 66748 — Humboldt, Kansas

Half of springs at Humboldt, KS see their last 32°F night by April 11; only one in ten is past it by March 27, and one in ten still has one after April 29. Planting tender crops after April 20 leaves a 30% risk of a frost on them, after April 23 20%, and after April 29 10%. The 18 days between the even-odds date and the one-in-ten date is the widest of the 110 Kansas stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 27 in half of years, as early as October 10 one year in ten, and holds off past November 9 one year in ten. A hard freeze of 28°F follows 8 days later, around November 4; in spring the one-in-ten date for 28°F is April 20, 9 days before the 32°F one. The freeze-free season lasts 195 days in a typical year, longer than at 72% of the 110 Kansas stations; it reaches 216 days one year in ten and falls short of 174 one year in ten. On average 111 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 12 days longer, to about April 23, and return around October 16. Severe cold of 16°F or below comes every winter, usually between December 5 and March 1.

July is the warmest month at Humboldt, KS, averaging 90°F by day and 69°F at night; January is the coldest at 42°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 80% of years.

Warmth for growing adds up to 4,223 growing degree days a year (base 50°F), more than at 65% of the 110 Kansas stations. 36% of them (1,512) have built up by the end of June, and July adds the most, 910. Precipitation totals 42.3 inches a year, most in May (5.8") and least in January (1.3"); May to September bring 58% of it.

The nearest other station, Iola 1 W, KS, 8 miles north of Humboldt, has a last frost 3 days earlier (April 8), a first frost 1 day earlier (October 26), a season 5 days longer.

The first measurable snow (0.1 inch or more) in Humboldt usually arrives around December 8, and the last of the season around February 11. Those are the middle dates across the winters of 1991–2020 at Humboldt, KS, 0.9 miles away: half of years saw snow earlier, half later. Snow fell in 95% of those winters. The last 32°F night of spring typically comes 59 days after the last snow.

ZIP 66748 is under a mile from Humboldt, KS, which stands at 940 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 66748 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.