Ammon, ID 83405 Frost Dates
Ammon, ID: when does the frost end?
Around 06/09 is the usual last spring frost, about 285 days away. Fall's first freeze usually shows up around 09/11, roughly 93 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Ammon in Zone 5b (-15 to -10°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
With roughly 2 weeks until Ammon's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
How much risk comes with planting early here
06/09 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/19 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/26 and only about 1 year in 10 sees frost after that.
Ammon against the rest of the dataset
Ammon's growing season runs about 93 days, ranking 39,861 of 40,283 US ZIP codes measured here, longest to shortest. Within ID, it ranks 260 of 320.
Learn more
Before leaning on 83405's figures: local microclimates explains what one yard in Ammon can differ from the 83405 normal, while zone vs. frost date explains why Zone 5b and Ammon's frost date answer different questions.