Herndon, VA 20101 Frost Dates
20101, near Herndon, VA: the frost window
Around 04/13 is the usual last spring frost, about 228 days away. Fall's first freeze usually shows up around 10/26, roughly 195 days after the last spring frost.
Zone 7a (0 to 5°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 Herndon, not a forecast for this year.
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.
Why 04/13 isn't a guarantee
04/13 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/29 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/01 and only about 1 year in 10 sees frost after that.
Herndon against the rest of the dataset
Herndon's growing season runs about 195 days, ranking 19,201 of 40,283 US ZIP codes measured here, longest to shortest. Within VA, it ranks 735 of 1,178.
Learn more
Two guides worth reading on 20101: 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 20101 normal.