New Berlin, WI 53151 Frost Dates
When can you plant in New Berlin, WI?
Around 05/03 is the usual last spring frost, about 248 days away. The first fall frost typically arrives around 10/14, about 162 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 New Berlin, not a forecast for this year.
What to do before the first frost
About 7 weeks of growing season left in New Berlin 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 04/18 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 New Berlin compares
At roughly 162 frost-free days, New Berlin places 31,626 of 40,283 ZIP codes in this dataset. Within WI, it ranks 254 of 860.
Learn more
local microclimates covers what one yard in New Berlin can differ from the 53151 normal. zone vs. frost date covers why Zone 5b and New Berlin's frost date answer different questions.