FrostDateCheck

Bronson, IA 51007 Frost Dates

When can you plant in Bronson, IA?

Zone 5a

The last spring frost here typically falls around 04/29, about 244 days from today. The first fall frost typically arrives around 10/05, about 159 frost-free days later.

The USDA Plant Hardiness Zone Map puts Bronson in Zone 5a (-20 to -15°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 5 weeks of growing season left in Bronson before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.

The actual range around Bronson's last frost

04/29 is the middle of 30 years of NOAA records, not a promise. Plant by 04/16 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 Bronson compares

Bronson's growing season runs about 159 days, ranking 32,760 of 40,283 US ZIP codes measured here, longest to shortest. Within IA, it ranks 797 of 1,042.

Learn more

local microclimates covers what one yard in Bronson can differ from the 51007 normal. zone vs. frost date covers why Zone 5a and Bronson's frost date answer different questions.