Frost Dates for 52772 — Tipton, Iowa

Half of springs at Tipton, IA see their last 32°F night by April 21; only one in ten is past it by April 8, and one in ten still has one after May 4. Planting tender crops after April 28 leaves a 30% risk of a frost on them, after May 1 20%, and after May 4 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 15 in half of years, as early as October 1 one year in ten, and holds off past October 28 one year in ten. A hard freeze of 28°F follows 10 days later, around October 25; in spring the one-in-ten date for 28°F is April 27, 7 days before the 32°F one. The freeze-free season lasts 175 days in a typical year, longer than at 81% of the 132 Iowa stations; it reaches 194 days one year in ten and falls short of 157 one year in ten. On average 150 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 10 days longer, to about May 1, and return around October 6. Severe cold of 16°F or below comes every winter, usually between November 23 and March 13.

July is the warmest month at Tipton, IA, averaging 84°F by day and 64°F at night; January is the coldest at 29°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 September the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 21% of years.

Warmth for growing adds up to 3,168 growing degree days a year (base 50°F), more than at 70% of the 132 Iowa stations. 36% of them (1,127) have built up by the end of June, and July adds the most, 738. Precipitation totals 36.5 inches a year, most in May (4.7") and least in January (1.4"); May to September bring 57% of it.

The nearest other station, Muscatine 2N, IA, 20 miles south of Tipton, has a last frost 3 days earlier (April 18), a first frost 7 days later (October 22), a season 9 days longer.

The first measurable snow (0.1 inch or more) in Tipton usually arrives around December 1, and the last of the season around March 19. Those are the middle dates across the winters of 1991–2020 at Tipton, IA, 2 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 33 days after the last snow.

ZIP 52772 is 2 miles from Tipton, IA, which stands at 820 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 52772 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.