Address reportCitiesSouth Carolina › Hilton Head Island

Hilton Head Island, SC

Earthquake hazard, typical weather and growing season from public federal data. Population 39,412.

Flood zone: it depends on the exact parcel

There is no such thing as a flood zone for a whole city. Two houses on the same street can sit in different zones, and it is the single fact here that changes most over a short distance. So this page does not guess one.

Look up a specific Hilton Head Island address →

Earthquake hazard high

Design category D

High seismic hazard. Strong ground shaking is expected over the life of a building. Substantial seismic-resistant design, detailing, and inspection are required by code. The ASCE 7 Seismic Design Category here is D. (Short-period design value Ss ≈ 0.448 g — the standard headline measure of ground-shaking hazard.)

USGS Seismic Design Web Services (ASCE 7), assuming Site Class D — stiff or unknown soil. Real soil conditions can move the category either way.

Typical weather

91.8° in July, 40.1° in January

Heads up: the nearest station with a full 30-year record is BEAUFORT MCAS, SC US, about 17 miles from here. Treat these as regional rather than local — terrain, elevation and water can change a lot in that distance.

Thirty-year averages, not a forecast. Any individual year can differ substantially.

MonthHighLowRainSnow
Jan60.3°40.1°2.9"0"
Feb63.7°42.8°2.91"0"
Mar69.9°48.7°3.11"0"
Apr77°56°3.06"0"
May84°64.3°2.5"0"
Jun88.9°71.3°4.99"0"
Jul91.8°74.5°5.57"0"
Aug90.3°74.1°6.5"0"
Sep85.7°69.5°4.03"0"
Oct78.1°59°3.77"0"
Nov69.3°48.4°2.51"0"
Dec62.7°42.9°3.17"0"

NOAA/NCEI 1991–2020 U.S. Climate Normals — station BEAUFORT MCAS, SC US, 17 mi away.

Growing season zone 9b

282 frost-free days

Last spring frost around March 3, first fall frost around December 9. Roughly half of years see frost outside that window.

2023 USDA Plant Hardiness Zone Map and NOAA/NCEI 1991–2020 frost normals.

What this page does not tell you

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