Grafton, IL 62037 Frost Dates
When can you plant in Grafton, IL?
Typically, the last spring freeze lands around 04/05, roughly 220 days out. The first fall frost typically arrives around 10/27, about 203 frost-free days later.
Zone 6b (-5 to 0°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Grafton, not a forecast for this year.
What to do before the first frost
About 9 weeks of growing season left in Grafton before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
How much risk comes with planting early here
04/05 is the middle of 30 years of NOAA records, not a promise. Plant by 03/22 and you're betting against frost in roughly 9 years out of 10. 04/21 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Grafton compares
About 203 days separate Grafton's last and first frost, putting it 17,002 of 40,283 ZIP codes nationally. Within IL, it ranks 169 of 1,548.
Learn more
local microclimates covers what one yard in Grafton can differ from the 62037 normal. zone vs. frost date covers why Zone 6b and Grafton's frost date answer different questions.