Frost Dates for 51012 — Cherokee, Iowa

Half of springs at Cherokee, IA see their last 32°F night by May 4; only one in ten is past it by April 20, and one in ten still has one after May 17. Planting tender crops after May 9 leaves a 30% risk of a frost on them, after May 13 20%, and after May 17 10%. The 13 days between the even-odds date and the one-in-ten date is narrower than at 42% of the 132 Iowa stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 4 in half of years, as early as September 20 one year in ten, and holds off past October 18 one year in ten. A hard freeze of 28°F follows 11 days later, around October 15; in spring the one-in-ten date for 28°F is May 7, 10 days before the 32°F one. The freeze-free season lasts 152 days in a typical year, shorter than at 92% of the 132 Iowa stations; it reaches 170 days one year in ten and falls short of 134 one year in ten. On average 165 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 13, and return around September 25. Severe cold of 16°F or below comes every winter, usually between November 10 and March 26.

July is the warmest month at Cherokee, IA, averaging 84°F by day and 62°F at night; January is the coldest at 27°F and 7°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 63% of years.

Warmth for growing adds up to 2,850 growing degree days a year (base 50°F), fewer than at 70% of the 132 Iowa stations. 34% of them (975) have built up by the end of June, and July adds the most, 719. Precipitation totals 31.4 inches a year, most in June (5.2") and least in January (0.7"); May to September bring 65% of it.

The nearest other station, Storm Lake, IA, 20 miles east of Cherokee and 232 feet higher, has a last frost 9 days earlier (April 25), a first frost 9 days later (October 13), a season 18 days longer.

The first measurable snow (0.1 inch or more) in Cherokee usually arrives around November 7, and the last of the season around April 10. Those are the middle dates across the winters of 1991–2020 at Cherokee, IA, 0.6 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 24 days after the last snow.

ZIP 51012 is under a mile from Cherokee, IA, which stands at 1,210 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 51012 in zone 5a, the band where the coldest night of the year averaged -20 to -15°F (-28.9 to -26.1°C) over 1991–2020; a zone describes winter lows, not frost dates.