Deconstruct SunHilton Head Island, SC: Hardiness Zone 9b & Sunlight by Season
Hilton Head Island is in USDA hardiness zone 9b. Here’s what that means for winter, plus sunrise, sunset, daylight hours and the sun’s path through the year.
Zone 9b in Hilton Head Island
On the 2023 USDA Plant Hardiness Zone Map, Hilton Head Island falls in zone 9b. That means the coldest night of a typical winter drops to between 25 and 30 °F. Perennials, shrubs and trees labeled for zone 9b or colder (a lower number) should survive the winter here. Parts of the area sit near the boundary with zone 9a, 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
- Savannah, GA Zone 9a
- Charleston, SC Zone 9a
- North Charleston, SC Zone 9a
- Mount Pleasant, SC Zone 9a
- Augusta, GA Zone 8b
- Columbia, SC Zone 8b
- Jacksonville, FL Zone 9b
- Myrtle Beach, SC Zone 8b
The sun over Hilton Head Island
On the June solstice the sun rises in the northeast at 6:16 AM and climbs to 81° above the horizon at 1:24 PM. On the December solstice the noon sun reaches only 34°, so a 20-foot tree casts a noon shadow about 29 feet long. In June the same tree’s noon shadow is only 3 feet.
Sunrise, sunset & daylight by month
| Date | Sunrise | Sunset | Daylight | Noon sun |
|---|---|---|---|---|
| Jan 21 | 7:22 AM | 5:46 PM | 10h 24m | 38° |
| Feb 21 | 6:59 AM | 6:14 PM | 11h 15m | 48° |
| Mar 21 | 7:25 AM | 7:35 PM | 12h 10m | 58° |
| Apr 21 | 6:47 AM | 7:56 PM | 13h 10m | 70° |
| May 21 | 6:21 AM | 8:17 PM | 13h 56m | 78° |
| Jun 21 | 6:16 AM | 8:32 PM | 14h 16m | 81° |
| Jul 21 | 6:30 AM | 8:27 PM | 13h 57m | 78° |
| Aug 21 | 6:51 AM | 8:00 PM | 13h 09m | 70° |
| Sep 21 | 7:10 AM | 7:20 PM | 12h 10m | 58° |
| Oct 21 | 7:31 AM | 6:43 PM | 11h 12m | 47° |
| Nov 21 | 6:57 AM | 5:20 PM | 10h 23m | 38° |
| Dec 21 | 7:19 AM | 5:22 PM | 10h 02m | 34° |
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 Hilton Head Island
Full sun is 6+ hours of direct sun. In Hilton Head Island an open spot has 14.3 hours of daylight to work with in June and 10.0 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 Hilton Head Island 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 Hilton Head Island, SC in?
Hilton Head Island, South Carolina is in USDA plant hardiness zone 9b on the 2023 map. The average coldest winter night is 25 to 30 °F (−3.9 to −1.1 °C). It is near the boundary with zone 9a.
How many hours of daylight does Hilton Head Island get?
About 14.3 hours on the June solstice (sunrise 6:16 AM, sunset 8:32 PM) and 10.0 hours on the December solstice (sunrise 7:19 AM, sunset 5:22 PM). Around the equinoxes it is close to 12 hours.
How many hours of sun does my Hilton Head Island 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 Hilton Head Island?
Zone 9b 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 9b 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 32.190, -80.738.