Hilton Head Island water temperature by month

Swimmable from May through October.

Month by month

Month Typical Feels
January 52° brisk
February 56° brisk
March 62° brisk
April 69° refreshing
May 75° perfect
June 81° bath-warm
July 86° bath-warm
August 85° bath-warm
September 80° bath-warm
October 73° perfect
November 66° refreshing
December 57° brisk

The year at a glance

swimmable 40° 50° 60° 70° 80° 90° 86° 52° JFMAMJJASOND January: typically 52° — brisk February: typically 56° — brisk March: typically 62° — brisk April: typically 69° — refreshing May: typically 75° — perfect June: typically 81° — bath-warm July: typically 86° — bath-warm August: typically 85° — bath-warm September: typically 80° — bath-warm October: typically 73° — perfect November: typically 66° — refreshing December: typically 57° — brisk

The water right now

Typically about 73° in October — perfect.

from the Fort Pulaski station at the Savannah River mouth, about 12 miles away

perfect

bath-warm 80° and up perfect 72–79° refreshing 65–71° brisk below 65° 73° typical for October

Twelve miles of sand flat and hard enough to bike on at low tide, and Lowcountry water that holds its summer warmth into October.

Jellyfish season

What usually turns up on the South Carolina coast, and when.

  • The sea nettle is the summer one. South Carolina’s Department of Natural Resources calls it common in the summer and says this species causes most of the jellyfish stings that occur in South Carolina waters. South Carolina's Department of Natural Resources — Sea Science: jellyfish
  • Cannonball jellies are the harmless crowd: during the summer and fall, large numbers appear near the coast and in the mouths of the estuaries, and they are one of the least venomous jellyfish here. South Carolina's Department of Natural Resources — Sea Science: jellyfish
  • Winter has its own. The lion’s mane — the winter jelly — typically appears during the colder months. South Carolina's Department of Natural Resources — Sea Science: jellyfish
  • The Portuguese man-of-war is a visitor rather than a resident here. It lives in the tropics, the subtropics and the Gulf Stream, and only drifts into nearshore South Carolina water infrequently, pushed by wind and current. South Carolina's Department of Natural Resources — Sea Science: jellyfish

This is what a season usually looks like, not a forecast of any particular week. Jellyfish drift on wind and current, so the people who watch them say there are tendencies but no guarantees — the lifeguard flags on the day beat any calendar.

About this reading

The Fort Pulaski station at the Savannah River mouth sits in an inlet; surf-zone water can run a few degrees off this reading.

Reading from the Fort Pulaski station at the Savannah River mouth, about 12 miles away.

Warm water says nothing about surf, rip currents, or bacteria — check local lifeguard flags and advisories.