Frost Dates for 61252 — Fulton, Illinois

Half of springs at Fulton L&D #13, IL see their last 32°F night by April 13; only one in ten is past it by April 1, and one in ten still has one after April 28. Planting tender crops after April 18 leaves a 30% risk of a frost on them, after April 23 20%, and after April 28 10%. The 15 days between the even-odds date and the one-in-ten date is narrower than at 54% of the 158 Illinois stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 26 in half of years, as early as October 13 one year in ten, and holds off past November 7 one year in ten. A hard freeze of 28°F follows 8 days later, around November 3; in spring the one-in-ten date for 28°F is April 18, 10 days before the 32°F one. The freeze-free season lasts 195 days in a typical year, longer than at 78% of the 158 Illinois stations; it reaches 215 days one year in ten and falls short of 174 one year in ten. On average 132 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 11 days longer, to about April 24, and return around October 16. Severe cold of 16°F or below comes every winter, usually between December 1 and March 10.

July is the warmest month at Fulton L&D #13, IL, averaging 84°F by day and 65°F at night; January is the coldest at 29°F and 14°F. A freezing night is all but certain in every month from November to April (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month.

Warmth for growing adds up to 3,245 growing degree days a year (base 50°F), fewer than at 68% of the 158 Illinois stations. 34% of them (1,119) have built up by the end of June, and July adds the most, 763. Precipitation totals 34.3 inches a year, most in June (4.5") and least in January (1.4"); May to September bring 55% of it.

The nearest other station, Clinton #1, IA, 8 miles southwest of Fulton, has a last frost 9 days later (April 22), a first frost 10 days earlier (October 16), a season 20 days shorter.

The first measurable snow (0.1 inch or more) in Fulton usually arrives around November 22, and the last of the season around March 24. Those are the middle dates across the winters of 1991–2020 at Clinton #1, IA, 7.7 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 20 days after the last snow.

ZIP 61252 is 2 miles from Fulton L&D #13, IL, which stands at 592 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station; its figures are presented in full for 52732 (Clinton). The 2023 USDA Plant Hardiness Zone Map lists ZIP 61252 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.