Oconomowoc Lake, WI 53069 Frost Dates
Frost dates for Oconomowoc Lake, WI, ZIP 53069
Around 04/30 is the usual last spring frost, about 245 days away. The first fall frost typically arrives around 10/12, about 164 frost-free days later.
Oconomowoc Lake sits in USDA Zone 5b (-15 to -10°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
Zone 5b around Oconomowoc Lake has about 6 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 04/30 isn't a guarantee
04/30 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. 05/17 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Oconomowoc Lake compares
Oconomowoc Lake's growing season runs about 164 days, ranking 31,113 of 40,283 US ZIP codes measured here, longest to shortest. Within WI, it ranks 217 of 860.
Learn more
zone vs. frost date explains why Zone 5b and Oconomowoc Lake's frost date answer different questions, and the frost range explains how to read the range around Oconomowoc Lake's dates instead of trusting one.