Herndon, VA 20152 Frost Dates
20152, near Herndon, VA: the frost window
Typically, the last spring freeze lands around 04/15, roughly 230 days out. Fall's first freeze usually shows up around 10/24, roughly 194 days after the last spring frost.
Herndon sits in USDA Zone 7a (0 to 5°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
Herndon's growing season runs out in roughly 8 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
How much risk comes with planting early here
04/15 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/31 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.
Herndon against the rest of the dataset
At roughly 194 frost-free days, Herndon places 19,440 of 40,283 ZIP codes in this dataset. Within VA, it ranks 758 of 1,178.
Learn more
Two guides worth reading on 20152: the frost range, on how to read the range around Herndon's dates instead of trusting one, and local microclimates, on what one yard in Herndon can differ from the 20152 normal.