Henderson, IL 61439 Frost Dates
When can you plant in Henderson, IL?
Typically, the last spring freeze lands around 04/20, roughly 235 days out. The first fall frost typically arrives around 10/19, about 180 frost-free days later.
The USDA Plant Hardiness Zone Map puts Henderson in Zone 5b (-15 to -10°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
About 7 weeks of growing season left in Henderson before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 04/20 isn't a guarantee
04/20 is the middle of 30 years of NOAA records, not a promise. Plant by 04/06 and you're betting against frost in roughly 9 years out of 10. 05/05 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Henderson compares
Henderson's growing season runs about 180 days, ranking 25,049 of 40,283 US ZIP codes measured here, longest to shortest. Within IL, it ranks 976 of 1,548.
Learn more
local microclimates covers what one yard in Henderson can differ from the 61439 normal. zone vs. frost date covers why Zone 5b and Henderson's frost date answer different questions.