Waterloo, IA 50703 Frost Dates
Frost dates for Waterloo, IA, ZIP 50703
Around 04/27 is the usual last spring frost, about 242 days away. The first fall frost typically arrives around 10/10, about 165 frost-free days later.
Zone 5a (-20 to -15°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 Waterloo, not a forecast for this year.
What to do before the first frost
Zone 5a around Waterloo has about 6 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
The actual range around Waterloo's last frost
04/27 is the middle of 30 years of NOAA records, not a promise. Plant by 04/11 and you're betting against frost in roughly 9 years out of 10. 05/10 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Waterloo compares
About 165 days separate Waterloo's last and first frost, putting it 30,495 of 40,283 ZIP codes nationally. Within IA, it ranks 486 of 1,042.
Learn more
the frost range explains how to read the range around Waterloo's dates instead of trusting one, and local microclimates explains what one yard in Waterloo can differ from the 50703 normal.