Sergeant Bluff, IA 51102 Frost Dates
Frost dates for Sergeant Bluff, IA, ZIP 51102
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.
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 Sergeant Bluff, not a forecast for this year.
What to do before the first frost
Zone 5a around Sergeant Bluff has about 5 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.
Why 04/29 isn't a guarantee
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 Sergeant Bluff compares
About 159 days separate Sergeant Bluff's last and first frost, putting it 32,642 of 40,283 ZIP codes nationally. Within IA, it ranks 779 of 1,042.
Learn more
local microclimates explains what one yard in Sergeant Bluff can differ from the 51102 normal, and zone vs. frost date explains why Zone 5a and Sergeant Bluff's frost date answer different questions.