Chaska, MN 55318 Frost Dates
Frost dates for Chaska, MN, ZIP 55318
Typically, the last spring freeze lands around 05/05, roughly 250 days out. The first fall frost typically arrives around 10/05, about 151 frost-free days later.
The USDA Plant Hardiness Zone Map puts Chaska in Zone 4b (-25 to -20°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
Zone 4b around Chaska 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 05/05 isn't a guarantee
05/05 is the middle of 30 years of NOAA records, not a promise. Plant by 04/21 and you're betting against frost in roughly 9 years out of 10. 05/19 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Chaska compares
At roughly 151 frost-free days, Chaska places 34,949 of 40,283 ZIP codes in this dataset. Within MN, it ranks 481 of 943.
Learn more
zone vs. frost date explains why Zone 4b and Chaska's frost date answer different questions, and the frost range explains how to read the range around Chaska's dates instead of trusting one.