Frost Dates for 52060 — Maquoketa, Iowa

Half of springs at Maquoketa, IA see their last 32°F night by April 25; only one in ten is past it by April 11, and one in ten still has one after May 9. Planting tender crops after May 2 leaves a 30% risk of a frost on them, after May 5 20%, and after May 9 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 14 in half of years, as early as September 30 one year in ten, and holds off past October 26 one year in ten. A hard freeze of 28°F follows 10 days later, around October 24; in spring the one-in-ten date for 28°F is May 1, 8 days before the 32°F one. The freeze-free season lasts 171 days in a typical year, longer than at 73% of the 132 Iowa stations; it reaches 189 days one year in ten and falls short of 151 one year in ten. On average 153 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 5, and return around October 3. Severe cold of 16°F or below comes every winter, usually between November 23 and March 14.

July is the warmest month at Maquoketa, IA, averaging 82°F by day and 63°F at night; January is the coldest at 27°F and 11°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 34% of years.

Warmth for growing adds up to 2,902 growing degree days a year (base 50°F), fewer than at 62% of the 132 Iowa stations. 35% of them (1,012) have built up by the end of June, and July adds the most, 699. Precipitation totals 36.7 inches a year, most in June (5.1") and least in January (1.3"); May to September bring 58% of it.

The nearest other station, Bellevue L&D 12, IA, 18 miles northeast of Maquoketa, has the same 50% last-frost date, a first frost 2 days later (October 16), a season 1 day longer.

The first measurable snow (0.1 inch or more) in Maquoketa usually arrives around November 22, and the last of the season around March 23. Those are the middle dates across the winters of 1991–2020 at Maquoketa, IA, 0.9 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 52060 is under a mile from Maquoketa, IA, which stands at 668 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 52060 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.