Hillsboro, IA 52630 Frost Dates
When can you plant in Hillsboro, IA?
Around 04/30 is the usual last spring frost, about 245 days away. The first fall frost typically arrives around 10/10, about 163 frost-free days later.
Zone 6a (-10 to -5°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 Hillsboro, not a forecast for this year.
What to do before the first frost
About 6 weeks of growing season left in Hillsboro before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 04/30 isn't a guarantee
04/30 is the middle of 30 years of NOAA records, not a promise. Plant by 04/13 and you're betting against frost in roughly 9 years out of 10. 05/14 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Hillsboro compares
Hillsboro's growing season runs about 163 days, ranking 31,546 of 40,283 US ZIP codes measured here, longest to shortest. Within IA, it ranks 682 of 1,042.
Learn more
local microclimates covers what one yard in Hillsboro can differ from the 52630 normal. zone vs. frost date covers why Zone 6a and Hillsboro's frost date answer different questions.