Montello, WI 53949 Frost Dates
When can you plant in Montello, WI?
Around 05/03 is the usual last spring frost, about 248 days away. The first fall frost typically arrives around 10/05, about 153 frost-free days later.
The USDA Plant Hardiness Zone Map puts Montello in Zone 5a (-20 to -15°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 5 weeks of growing season left in Montello before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 05/03 isn't a guarantee
05/03 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. 05/18 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Montello compares
Montello's growing season runs about 153 days, ranking 34,559 of 40,283 US ZIP codes measured here, longest to shortest. Within WI, it ranks 507 of 860.
Learn more
zone vs. frost date covers why Zone 5a and Montello's frost date answer different questions. the frost range covers how to read the range around Montello's dates instead of trusting one.