Frost Dates for 50841 — Corning, Iowa

Half of springs at Corning, IA see their last 32°F night by April 27; only one in ten is past it by April 13, and one in ten still has one after May 11. Planting tender crops after May 3 leaves a 30% risk of a frost on them, after May 6 20%, and after May 11 10%. The 14 days between the even-odds date and the one-in-ten date is wider than at 58% of the 132 Iowa stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 12 in half of years, as early as September 26 one year in ten, and holds off past October 26 one year in ten. A hard freeze of 28°F follows 11 days later, around October 23; in spring the one-in-ten date for 28°F is May 1, 10 days before the 32°F one. The freeze-free season lasts 168 days in a typical year, longer than at 62% of the 132 Iowa stations; it reaches 188 days one year in ten and falls short of 147 one year in ten. On average 148 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 6, and return around October 2. Severe cold of 16°F or below comes every winter, usually between November 19 and March 17.

July is the warmest month at Corning, IA, averaging 85°F by day and 64°F at night; January is the coldest at 31°F and 12°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 38% of years.

Warmth for growing adds up to 3,122 growing degree days a year (base 50°F), more than at 64% of the 132 Iowa stations. 34% of them (1,064) have built up by the end of June, and July adds the most, 750. Precipitation totals 35.3 inches a year, most in May (5.2") and least in January (0.8"); May to September bring 61% of it.

The nearest other station, Creston 2 SW, IA, 19 miles east of Corning, has a last frost 1 day later (April 28), a first frost 1 day earlier (October 11), a season 4 days shorter.

The first measurable snow (0.1 inch or more) in Corning usually arrives around November 30, and the last of the season around March 19. Those are the middle dates across the winters of 1991–2020 at Corning, IA, 1 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 39 days after the last snow.

ZIP 50841 is 1 mile from Corning, IA, which stands at 1,190 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 50841 in zone 5b, the band where the coldest night of the year averaged -15 to -10°F (-26.1 to -23.3°C) over 1991–2020; a zone describes winter lows, not frost dates.