Tiffin, IA 52340 Frost Dates
When can you plant in Tiffin, IA?
Around 04/21 is the usual last spring frost, about 236 days away. The first fall frost typically arrives around 10/18, about 180 frost-free days later.
The USDA Plant Hardiness Zone Map puts Tiffin 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 Tiffin before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Tiffin's last frost
04/21 is the middle of 30 years of NOAA records, not a promise. Plant by 04/05 and you're betting against frost in roughly 9 years out of 10. 05/06 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Tiffin compares
At roughly 180 frost-free days, Tiffin places 24,837 of 40,283 ZIP codes in this dataset. Within IA, it ranks 91 of 1,042.
Learn more
local microclimates covers what one yard in Tiffin can differ from the 52340 normal. zone vs. frost date covers why Zone 5b and Tiffin's frost date answer different questions.