Lewis, IA 51544 Frost Dates
Lewis, IA: when does the frost end?
The last spring frost here typically falls around 04/30, about 245 days from today. Fall's first freeze usually shows up around 10/02, roughly 153 days after the last spring frost.
Lewis 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.
Stretching the season past the first frost
With roughly 5 weeks until Lewis's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Lewis's last frost
04/30 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/17 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/15 and only about 1 year in 10 sees frost after that.
Lewis against the rest of the dataset
At roughly 153 frost-free days, Lewis places 34,615 of 40,283 ZIP codes in this dataset. Within IA, it ranks 933 of 1,042.
Learn more
Before leaning on 51544's figures: local microclimates explains what one yard in Lewis can differ from the 51544 normal, while zone vs. frost date explains why Zone 5b and Lewis's frost date answer different questions.