Tombstone, AZ 85655 Frost Dates
Tombstone, AZ: when does the frost end?
Around 04/14 is the usual last spring frost, about 229 days away. Fall's first freeze usually shows up around 11/02, roughly 200 days after the last spring frost.
Tombstone sits in USDA Zone 8a (10 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 9 weeks until Tombstone's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 04/14 isn't a guarantee
04/14 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/28 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/30 and only about 1 year in 10 sees frost after that.
Tombstone against the rest of the dataset
Tombstone's growing season runs about 200 days, ranking 17,832 of 40,283 US ZIP codes measured here, longest to shortest. Within AZ, it ranks 387 of 506.
Learn more
Before leaning on 85655's figures: the frost range explains how to read the range around Tombstone's dates instead of trusting one, while local microclimates explains what one yard in Tombstone can differ from the 85655 normal.