Smithboro, IL 62284 Frost Dates
When can you plant in Smithboro, IL?
Typically, the last spring freeze lands around 04/06, roughly 221 days out. The first fall frost typically arrives around 10/29, about 204 frost-free days later.
Smithboro sits in USDA Zone 6b (-5 to 0°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
What to do before the first frost
About 9 weeks of growing season left in Smithboro before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Smithboro's last frost
04/06 is the middle of 30 years of NOAA records, not a promise. Plant by 03/23 and you're betting against frost in roughly 9 years out of 10. 04/22 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Smithboro compares
Smithboro's growing season runs about 204 days, ranking 16,785 of 40,283 US ZIP codes measured here, longest to shortest. Within IL, it ranks 147 of 1,548.
Learn more
the frost range covers how to read the range around Smithboro's dates instead of trusting one. local microclimates covers what one yard in Smithboro can differ from the 62284 normal.