Mason, WI 54856 Frost Dates
When can you plant in Mason, WI?
Around 05/23 is the usual last spring frost, about 268 days away. The first fall frost typically arrives around 09/29, about 125 frost-free days later.
Mason sits in USDA Zone 4b (-25 to -20°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
What to do before the first frost
About 5 weeks of growing season left in Mason before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 05/23 isn't a guarantee
05/23 is the middle of 30 years of NOAA records, not a promise. Plant by 05/08 and you're betting against frost in roughly 9 years out of 10. 06/06 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Mason compares
About 125 days separate Mason's last and first frost, putting it 38,821 of 40,283 ZIP codes nationally. Within WI, it ranks 823 of 860.
Learn more
the frost range covers how to read the range around Mason's dates instead of trusting one. local microclimates covers what one yard in Mason can differ from the 54856 normal.