Pacific Junction, IA 51561 Frost Dates
Frost dates for Pacific Junction, IA, ZIP 51561
Around 04/23 is the usual last spring frost, about 238 days away. The first fall frost typically arrives around 10/11, about 170 frost-free days later.
Pacific Junction 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 Pacific Junction 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.
How much risk comes with planting early here
04/23 is the middle of 30 years of NOAA records, not a promise. Plant by 04/09 and you're betting against frost in roughly 9 years out of 10. 05/06 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Pacific Junction compares
At roughly 170 frost-free days, Pacific Junction places 29,269 of 40,283 ZIP codes in this dataset. Within IA, it ranks 327 of 1,042.
Learn more
local microclimates explains what one yard in Pacific Junction can differ from the 51561 normal, and zone vs. frost date explains why Zone 5b and Pacific Junction's frost date answer different questions.