Montezuma, IA 50171 Frost Dates
Frost dates for Montezuma, IA, ZIP 50171
Around 05/03 is the usual last spring frost, about 248 days away. The first fall frost typically arrives around 10/06, about 155 frost-free days later.
Zone 5b (-15 to -10°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 Montezuma, not a forecast for this year.
What to do before the first frost
Zone 5b around Montezuma 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 Montezuma's last frost
05/03 is the middle of 30 years of NOAA records, not a promise. Plant by 04/19 and you're betting against frost in roughly 9 years out of 10. 05/17 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Montezuma compares
About 155 days separate Montezuma's last and first frost, putting it 34,025 of 40,283 ZIP codes nationally. Within IA, it ranks 871 of 1,042.
Learn more
local microclimates explains what one yard in Montezuma can differ from the 50171 normal, and zone vs. frost date explains why Zone 5b and Montezuma's frost date answer different questions.