Dover, ID 83860 Frost Dates
Frost dates for Dover, ID, ZIP 83860
Around 05/08 is the usual last spring frost, about 253 days away. The first fall frost typically arrives around 09/28, about 141 frost-free days later.
Dover sits in USDA Zone 6b (-5 to 0°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 6b around Dover has about 4 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.
The actual range around Dover's last frost
05/08 is the middle of 30 years of NOAA records, not a promise. Plant by 04/23 and you're betting against frost in roughly 9 years out of 10. 05/25 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Dover compares
About 141 days separate Dover's last and first frost, putting it 36,926 of 40,283 ZIP codes nationally. Within ID, it ranks 147 of 320.
Learn more
zone vs. frost date explains why Zone 6b and Dover's frost date answer different questions, and the frost range explains how to read the range around Dover's dates instead of trusting one.