Frost Dates for 52136 — Cresco, Iowa

Half of springs at Cresco 1 NE, IA see their last 32°F night by May 8; only one in ten is past it by April 25, and one in ten still has one after May 21. Planting tender crops after May 14 leaves a 30% risk of a frost on them, after May 17 20%, and after May 21 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 1 in half of years, as early as September 19 one year in ten, and holds off past October 14 one year in ten. A hard freeze of 28°F follows 10 days later, around October 11; in spring the one-in-ten date for 28°F is May 13, 8 days before the 32°F one. The freeze-free season lasts 147 days in a typical year, shorter than at 98% of the 132 Iowa stations; it reaches 163 days one year in ten and falls short of 127 one year in ten. On average 170 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 17, and return around September 24. Severe cold of 16°F or below comes every winter, usually between November 11 and March 30.

July is the warmest month at Cresco 1 NE, IA, averaging 83°F by day and 60°F at night; January is the coldest at 24°F and 6°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 76% of years.

Warmth for growing adds up to 2,568 growing degree days a year (base 50°F), fewer than at 96% of the 132 Iowa stations. 34% of them (866) have built up by the end of June, and July adds the most, 663. Precipitation totals 38.1 inches a year, most in June (6.3") and least in January (1.1"); May to September bring 63% of it.

The nearest other station, Decorah, IA, 16 miles east of Cresco and 395 feet lower, has a last frost 5 days earlier (May 3), a first frost 6 days later (October 7), a season 10 days longer.

The first measurable snow (0.1 inch or more) in Cresco usually arrives around November 13, and the last of the season around April 9. Those are the middle dates across the winters of 1991–2020 at Cresco 1 NE, IA, 0.7 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 29 days after the last snow.

ZIP 52136 is under a mile from Cresco 1 NE, IA, which stands at 1,255 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 52136 in zone 4b, the band where the coldest night of the year averaged -25 to -20°F (-31.7 to -28.9°C) over 1991–2020; a zone describes winter lows, not frost dates.