Mountain Brook, AL 35213 Frost Dates
Frost dates for Mountain Brook, AL, ZIP 35213
Around 03/21 is the usual last spring frost, about 205 days away. The first fall frost typically arrives around 11/11, about 236 frost-free days later.
Zone 8b (15 to 20°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Mountain Brook, not a forecast for this year.
What to do before the first frost
Zone 8b around Mountain Brook has about 11 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
03/21 is the middle of 30 years of NOAA records, not a promise. Plant by 02/28 and you're betting against frost in roughly 9 years out of 10. 04/08 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Mountain Brook compares
About 236 days separate Mountain Brook's last and first frost, putting it 9,326 of 40,283 ZIP codes nationally. Within AL, it ranks 371 of 809.
Learn more
the frost range explains how to read the range around Mountain Brook's dates instead of trusting one, and local microclimates explains what one yard in Mountain Brook can differ from the 35213 normal.