Herndon, VA 20166 Frost Dates
When can you plant in Herndon, VA?
Typically, the last spring freeze lands around 04/13, roughly 228 days out. The first fall frost typically arrives around 10/26, about 195 frost-free days later.
The USDA Plant Hardiness Zone Map puts Herndon in Zone 7a (0 to 5°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
About 8 weeks of growing season left in Herndon before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 04/13 isn't a guarantee
04/13 is the middle of 30 years of NOAA records, not a promise. Plant by 03/29 and you're betting against frost in roughly 9 years out of 10. 05/01 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Herndon compares
Herndon's growing season runs about 195 days, ranking 19,205 of 40,283 US ZIP codes measured here, longest to shortest. Within VA, it ranks 739 of 1,178.
Learn more
the frost range covers how to read the range around Herndon's dates instead of trusting one. local microclimates covers what one yard in Herndon can differ from the 20166 normal.