Granger, IA 50109 Frost Dates
50109, near Granger, IA: the frost window
Typically, the last spring freeze lands around 04/19, roughly 234 days out. Fall's first freeze usually shows up around 10/18, roughly 179 days after the last spring frost.
Granger 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
Granger's growing season runs out in roughly 7 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
The actual range around Granger'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.
Granger against the rest of the dataset
Granger's growing season runs about 179 days, ranking 25,343 of 40,283 US ZIP codes measured here, longest to shortest. Within IA, it ranks 104 of 1,042.
Learn more
Two guides worth reading on 50109: the frost range, on how to read the range around Granger's dates instead of trusting one, and local microclimates, on what one yard in Granger can differ from the 50109 normal.