Williamsburg, IA 52334 Frost Dates
Williamsburg, IA: when does the frost end?
The last spring frost here typically falls around 04/28, about 243 days from today. Fall's first freeze usually shows up around 10/09, roughly 164 days after the last spring frost.
Williamsburg sits in USDA Zone 5a (-20 to -15°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 6 weeks until Williamsburg's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 04/28 isn't a guarantee
04/28 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/14 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/12 and only about 1 year in 10 sees frost after that.
Williamsburg against the rest of the dataset
Williamsburg's growing season runs about 164 days, ranking 30,938 of 40,283 US ZIP codes measured here, longest to shortest. Within IA, it ranks 588 of 1,042.
Learn more
Before leaning on 52334's figures: the frost range explains how to read the range around Williamsburg's dates instead of trusting one, while local microclimates explains what one yard in Williamsburg can differ from the 52334 normal.