Herndon, VA 20103 Frost Dates
Herndon, VA: when does the frost end?
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
With roughly 8 weeks until Herndon's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
How much risk comes with planting early here
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 19,202 of 40,283 US ZIP codes measured here, longest to shortest. Within VA, it ranks 736 of 1,178.
Learn more
Before leaning on 20103's figures: zone vs. frost date explains why Zone 7a and Herndon's frost date answer different questions, while the frost range explains how to read the range around Herndon's dates instead of trusting one.