FrostDateCheck

Polk City, IA 50226 Frost Dates

Polk City, IA: when does the frost end?

Zone 5b

The last spring frost here typically falls around 04/19, about 234 days from today. Fall's first freeze usually shows up around 10/18, roughly 179 days after the last spring frost.

Polk City 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 7 weeks until Polk City's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.

The actual range around Polk City's last frost

04/19 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/05 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/03 and only about 1 year in 10 sees frost after that.

Polk City against the rest of the dataset

At roughly 179 frost-free days, Polk City places 25,273 of 40,283 ZIP codes in this dataset. Within IA, it ranks 101 of 1,042.

Learn more

Before leaning on 50226's figures: local microclimates explains what one yard in Polk City can differ from the 50226 normal, while zone vs. frost date explains why Zone 5b and Polk City's frost date answer different questions.