Herndon, VA 20190 Frost Dates
Herndon, VA: 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 10/29, roughly 198 days after the last spring frost.
Zone 7b (5 to 10°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
With roughly 9 weeks until Herndon's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Herndon's last frost
04/14 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/30 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/28 and only about 1 year in 10 sees frost after that.
Herndon against the rest of the dataset
At roughly 198 frost-free days, Herndon places 18,348 of 40,283 ZIP codes in this dataset. Within VA, it ranks 687 of 1,178.
Learn more
Before leaning on 20190's figures: the frost range explains how to read the range around Herndon's dates instead of trusting one, while local microclimates explains what one yard in Herndon can differ from the 20190 normal.