Deconstruct Sun

Mount Pleasant, SC: Hardiness Zone 9a & Sunlight by Season

Mount Pleasant is in USDA hardiness zone 9a. Here’s what that means for winter, plus sunrise, sunset, daylight hours and the sun’s path through the year.

Hardiness zone
9a
2023 USDA map
Coldest winter night (avg)
20 to 25 °F
−6.7 to −3.9 °C
Longest day (Jun 21)
14h 19m
6:11 AM – 8:30 PM
Shortest day (Dec 21)
9h 59m
7:17 AM – 5:17 PM

Zone 9a in Mount Pleasant

On the 2023 USDA Plant Hardiness Zone Map, Mount Pleasant falls in zone 9a. That means the coldest night of a typical winter drops to between 20 and 25 °F. Perennials, shrubs and trees labeled for zone 9a or colder (a lower number) should survive the winter here.

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

All South Carolina hardiness zones →

The sun over Mount Pleasant

On the June solstice the sun rises in the northeast at 6:11 AM and climbs to 81° above the horizon at 1:21 PM. On the December solstice the noon sun reaches only 34°, so a 20-foot tree casts a noon shadow about 30 feet long. In June the same tree’s noon shadow is only 3 feet.

0°15°30°45°60°75°90°NNEESESSWWNWN
June solsticeMarch & September equinoxDecember solstice

Open the interactive sun calculator for Mount Pleasant

Sunrise, sunset & daylight by month

DateSunriseSunsetDaylightNoon sun
Jan 217:20 AM5:41 PM10h 22m37°
Feb 216:56 AM6:10 PM11h 14m47°
Mar 217:21 AM7:31 PM12h 10m58°
Apr 216:42 AM7:54 PM13h 11m69°
May 216:16 AM8:15 PM13h 59m78°
Jun 216:11 AM8:30 PM14h 19m81°
Jul 216:26 AM8:25 PM14h 00m78°
Aug 216:46 AM7:57 PM13h 11m69°
Sep 217:07 AM7:17 PM12h 10m58°
Oct 217:28 AM6:39 PM11h 11m46°
Nov 216:55 AM5:15 PM10h 20m37°
Dec 217:17 AM5:17 PM9h 59m34°

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

0h6h12h18h24hJanuary: 10h 22mJanFebruary: 11h 14mFebMarch: 12h 10mMarApril: 13h 11mAprMay: 13h 59mMayJune: 14h 19mJunJuly: 14h 00mJulAugust: 13h 11mAugSeptember: 12h 10mSepOctober: 11h 11mOctNovember: 10h 20mNovDecember: 9h 59mDec

What “full sun” means in Mount Pleasant

Full sun is 6+ hours of direct sun. In Mount Pleasant 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.

Full sun6+ hoursof direct sun
Part sun4–6 hoursof direct sun
Part shade2–4 hoursof direct sun
Full shadeUnder 2 hoursof direct sun

Measure the sun in your Mount Pleasant 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.

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Questions

What hardiness zone is Mount Pleasant, SC in?

Mount Pleasant, South Carolina is in USDA plant hardiness zone 9a on the 2023 map. The average coldest winter night is 20 to 25 °F (−6.7 to −3.9 °C).

How many hours of daylight does Mount Pleasant get?

About 14.3 hours on the June solstice (sunrise 6:11 AM, sunset 8:30 PM) and 10.0 hours on the December solstice (sunrise 7:17 AM, sunset 5:17 PM). Around the equinoxes it is close to 12 hours.

How many hours of sun does my Mount Pleasant 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 Mount Pleasant?

Zone 9a 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 9a 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 32.808, -79.865.