Deconstruct SunAlexandria, VA: Hardiness Zone 8a & Sunlight by Season
Alexandria is in USDA hardiness zone 8a. Here’s what that means for winter, plus sunrise, sunset, daylight hours and the sun’s path through the year.
Zone 8a in Alexandria
On the 2023 USDA Plant Hardiness Zone Map, Alexandria falls in zone 8a. That means the coldest night of a typical winter drops to between 10 and 15 °F. Perennials, shrubs and trees labeled for zone 8a or colder (a lower number) should survive the winter here. Parts of the area sit near the boundary with zone 7b, so a sheltered courtyard or an exposed hilltop can behave like the neighboring zone.
A zone only covers winter cold. For a plant to do well it also needs the right amount of sun, and that varies far more from one corner of a yard to the next than the zone does across town.
This is not the official USDA Plant Hardiness Zone Map. Zones are derived from the official 2023 dataset, resampled to about 2 km.
Nearby cities
- Arlington, VA Zone 7b
- Washington, DC Zone 8a
- Silver Spring, MD Zone 7b
- Rockville, MD Zone 7b
- Gaithersburg, MD Zone 7b
- Germantown, MD Zone 7b
- Columbia, MD Zone 7b
- Annapolis, MD Zone 8a
The sun over Alexandria
On the June solstice the sun rises in the northeast at 5:43 AM and climbs to 75° above the horizon at 1:10 PM. On the December solstice the noon sun reaches only 28°, so a 20-foot tree casts a noon shadow about 38 feet long. In June the same tree’s noon shadow is only 6 feet.
Sunrise, sunset & daylight by month
| Date | Sunrise | Sunset | Daylight | Noon sun |
|---|---|---|---|---|
| Jan 21 | 7:22 AM | 5:17 PM | 9h 55m | 31° |
| Feb 21 | 6:51 AM | 5:52 PM | 11h 01m | 41° |
| Mar 21 | 7:10 AM | 7:21 PM | 12h 11m | 52° |
| Apr 21 | 6:23 AM | 7:51 PM | 13h 28m | 63° |
| May 21 | 5:51 AM | 8:19 PM | 14h 28m | 72° |
| Jun 21 | 5:43 AM | 8:36 PM | 14h 53m | 75° |
| Jul 21 | 6:00 AM | 8:28 PM | 14h 29m | 72° |
| Aug 21 | 6:27 AM | 7:54 PM | 13h 27m | 63° |
| Sep 21 | 6:55 AM | 7:06 PM | 12h 12m | 52° |
| Oct 21 | 7:23 AM | 6:21 PM | 10h 58m | 40° |
| Nov 21 | 6:57 AM | 4:50 PM | 9h 53m | 31° |
| Dec 21 | 7:23 AM | 4:49 PM | 9h 27m | 28° |
Local time (New York), including daylight saving time. “Noon sun” is the sun’s height above the horizon at solar noon.
Daylight through the year
What “full sun” means in Alexandria
Full sun is 6+ hours of direct sun. In Alexandria an open spot has 14.9 hours of daylight to work with in June and 9.4 in December, so a bed that clears 6 hours in summer can easily drop to part shade in winter once the low sun slips behind trees and houses.
Measure the sun in your Alexandria yard
Daylight is the ceiling. Deconstruct Sun traces the trees and buildings around one exact spot and tells you its real direct-sun hours, today and at every solstice and equinox.
Questions
What hardiness zone is Alexandria, VA in?
Alexandria, Virginia is in USDA plant hardiness zone 8a on the 2023 map. The average coldest winter night is 10 to 15 °F (−12.2 to −9.4 °C). It is near the boundary with zone 7b.
How many hours of daylight does Alexandria get?
About 14.9 hours on the June solstice (sunrise 5:43 AM, sunset 8:36 PM) and 9.4 hours on the December solstice (sunrise 7:23 AM, sunset 4:49 PM). Around the equinoxes it is close to 12 hours.
How many hours of sun does my Alexandria yard get?
Up to the daylight hours above, minus whatever trees, buildings and fences block. In winter, when the sun stays low, that can be most of it. The Deconstruct Sun iPhone app measures the real direct-sun hours for one exact spot by having you trace what is around it.
When is the best time to plant in Alexandria?
Zone 8a tells you which perennials survive winter, not planting dates. For timing, use your local average frost dates from your county extension office, and choose plants rated for zone 8a or colder.
Source: USDA Plant Hardiness Zone Map, 2023. Agricultural Research Service, U.S. Department of Agriculture, planthardiness.ars.usda.gov. Underlying data © PRISM Group, Oregon State University, prism.oregonstate.edu, accessed 2026-08-30. Sun times calculated for 38.819, -77.084.