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Will it freeze in Herndon in the next 7 nights?
No overnight lows at or below 32°F are forecast in Herndon during the next 7 nights in the available NWS frost forecast.
Tonight: forecast low 59°F. Above 36°F.
NWS forecast period: Thu, Nov 5, 6:00 PM EST to Fri, Nov 6, 6:00 AM EST.
No nights at or below 36°F in the National Weather Service forecast for the next 7 nights.
- Tonight 59°F Above 36°F · Chance Rain Showers
- Fri, Nov 6 48°F Above 36°F · Mostly Cloudy
- Sat, Nov 7 43°F Above 36°F · Mostly Clear
- Sun, Nov 8 41°F Above 36°F · Mostly Clear
- Mon, Nov 9 39°F Above 36°F · Mostly Clear
- Tue, Nov 10 42°F Above 36°F · Mostly Clear
- Wed, Nov 11 38°F Above 36°F · Partly Cloudy
Overnight lows from the National Weather Service forecast for this location. This covers the available forecast window, not the first freeze of the whole season. Frost can form above 32°F on clear, calm nights.
Frost and freeze probabilities
Freeze dates shift from year to year. Spring percentages describe the chance of a freeze after the stated date; fall percentages describe the chance of a freeze by that date. The 10% spring date is the cautious one: a later freeze happens about 1 year in 10.
These dates describe historical probabilities, not this year’s forecast or the earliest and latest possible freezes. Different weather stations or probability thresholds can produce different published dates for the same city.
Average first hard freeze in Herndon
The median first fall hard-freeze date (28°F) is November 4, from NOAA’s 1991–2020 Climate Normals at Washington Dc Dulles Airport. This is the 50% probability date, not a forecast for this year.
| Temperature | Last spring date 90% · 50% · 10% chance of a later freeze | First fall date 10% · 50% · 90% chance of an earlier freeze | Season |
|---|---|---|---|
| 36°F frost possible | Apr 12 · Apr 29 · May 17 | Oct 2 · Oct 14 · Oct 27 | 170 days |
| 32°F freeze | Mar 31 · Apr 15 · Apr 30 | Oct 10 · Oct 24 · Nov 5 | 194 days |
| 28°F hard freeze | Mar 18 · Apr 1 · Apr 16 | Oct 21 · Nov 4 · Nov 19 | 218 days |
Average high temperature by month
1991–2020 normals at Washington Dc Dulles Airport
Average low temperature by month
Months with lows near or below freezing carry frost risk
Where these frost dates come from
The frost dates for Herndon, VA come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Washington Dc Dulles Airport (station USW00093738, elevation 290 ft), 4.6 mi from Herndon. Local conditions (valleys, hilltops, distance to water, city heat) can shift frost dates by days or weeks. The hardiness zone is from the 2023 USDA Plant Hardiness Zone Map (USDA ARS and Oregon State University PRISM). See our methodology.
Frost dates near Herndon
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Vienna, VA | 8.7 mi | Apr 14 | Oct 29 |
| Fairfax, VA | 9.3 mi | Apr 14 | Oct 29 |
| Poolesville, MD | 12 mi | Apr 13 | Oct 26 |
| Falls Church, VA | 13 mi | Apr 9 | Oct 31 |
| Leesburg, VA | 13 mi | Apr 16 | Oct 25 |
| Manassas Park, VA | 14 mi | Apr 12 | Oct 27 |
| Rockville, MD | 15 mi | Apr 1 | Nov 6 |
| Gaithersburg, MD | 16 mi | Apr 1 | Nov 6 |
| Manassas, VA | 16 mi | Apr 12 | Oct 27 |
| Alexandria, VA | 19 mi | Mar 24 | Nov 18 |
Frequently asked questions
When is the last frost in Herndon?
On average, the last spring frost (32°F) in Herndon is around April 15. In about 1 year in 10 it comes after April 30, and in 9 years in 10 it comes after March 31.
When is the first frost in Herndon?
The first fall frost (32°F) usually arrives around October 24. There’s a 10% chance of a freeze by October 10 and a 90% chance by November 5.
Can it frost in Herndon after the last frost date?
Yes. Frost can form on clear, calm nights even when the air stays above 32°F. Temperatures of 36°F or lower, cold enough for frost on exposed plants, have a 50% chance of occurring after April 29.
What growing zone is Herndon?
Herndon is in USDA Plant Hardiness Zone 7b (average annual extreme minimum temperature 5 to 10°F), based on the 2023 USDA map for ZIP code 20170. See growing zones in Virginia.
More: all Virginia frost dates · Virginia growing zones · UV index today in Herndon · frost vs. freeze