Sea surface temperature guide

Blue Marlin sea surface temperature guide.

  • Makaira nigricans
  • Billfish
  • Agency-reported threshold data

Blue marlin are warm-water fish — they live in the hottest offshore water available. Gulf of Mexico oil rigs in summer and Mid-Atlantic canyon edges in August are the two flagship US fisheries.

SST threshold gauge

The temperature ranges that matter.

The water temperature ranges that determine where blue marlin hold and feed. Hard thresholds (dashed lines) are values outside which fish actively depart or become inactive.

50°55°60°65°70°75°80°85°90°Peak 7682°
Outside toleranceSuboptimalGoodPeak·Dashed line = hard threshold
Optimal range76–82°F
Preferred range72–86°F
Avoid below68°F
Avoid above
Threshold source (Agency-reported) →

Depth profile & SST reliability

Typical depth

01000 feet

SST as locator

Moderate — SST is a partial signal

Blue marlin feed throughout the upper water column. SST is predictive but they will hunt deep when bait suspends.

Current systems & structure

Gulf StreamWarm core eddiesTemperature breaks

Blue marlin live in the warmest offshore water available. Gulf Stream core, warm core eddies, and tropical Atlantic and Gulf waters during summer.

Zone-by-zone calendar

Overlap charts by zone.

For each zone where blue marlin are present, the chart overlays the zone's typical monthly SST range with the species' preferred and optimal ranges. Months where the bands overlap are when fish are in range.

Mid-Atlantic

Baltimore & Wilmington CanyonsCape May NJ · Ocean City MD

Best months

July, August

MonthZone SSTStatus
Jan4654°FOutside
Feb4654°FOutside
Mar4856°FOutside
Apr5060°FOutside
May5666°FOutside
Junnow6474°FFishable
Jul7080°FPeak
Aug7282°FPeak
Sep6876°FFishable
Oct6068°FOutside
Nov5462°FOutside
Dec4856°FOutside
Norfolk & Washington CanyonsVirginia Beach VA · Wachapreague VA

Best months

June, July, August, September

MonthZone SSTStatus
Jan4858°FOutside
Feb4856°FOutside
Mar5060°FOutside
Apr5464°FOutside
May6070°FOutside
Junnow6878°FPeak
Jul7282°FPeak
Aug7484°FPeak
Sep7080°FPeak
Oct6472°FOutside
Nov5664°FOutside
Dec5060°FOutside
Cape Hatteras & Point OffshoreWanchese NC · Hatteras NC

Best months

June, July, August, September, October

MonthZone SSTStatus
Jan5866°FOutside
Feb5664°FOutside
Mar5866°FOutside
Apr6472°FOutside
May6876°FFishable
Junnow7482°FPeak
Jul7884°FPeak
Aug7884°FPeak
Sep7682°FPeak
Oct7078°FPeak
Nov6472°FOutside
Dec6068°FOutside

South Atlantic

Onslow Bay & Morehead City OffshoreMorehead City NC · Beaufort NC

Best months

May, June, July, August, September, October

MonthZone SSTStatus
Jan5866°FOutside
Feb5664°FOutside
Mar6068°FOutside
Apr6674°FFishable
May7078°FPeak
Junnow7482°FPeak
Jul7884°FPeak
Aug7884°FPeak
Sep7682°FPeak
Oct7078°FPeak
Nov6472°FOutside
Dec6068°FOutside
Southeast Florida Gulf Stream AccessPalm Beach FL · Fort Lauderdale FL

Best months

January, March, April, May, June, September, October, November, December

MonthZone SSTStatus
Jan7278°FPeak
Feb7276°FFishable
Mar7480°FPeak
Apr7680°FPeak
May7882°FPeak
Junnow8084°FPeak
Jul8286°FFishable
Aug8286°FFishable
Sep8084°FPeak
Oct7882°FPeak
Nov7480°FPeak
Dec7278°FPeak

Gulf of Mexico

Alabama & Mississippi Canyon OffshoreOrange Beach AL · Dauphin Island AL

Best months

April, May, June, September, October

MonthZone SSTStatus
Jan6270°FOutside
Feb6268°FOutside
Mar6672°FOutside
Apr7280°FPeak
May7682°FPeak
Junnow8084°FPeak
Jul8286°FFishable
Aug8286°FFishable
Sep8084°FPeak
Oct7480°FPeak
Nov6876°FFishable
Dec6472°FOutside
Louisiana Deepwater & RigsVenice LA · Grand Isle LA

Best months

April, May, June, September, October, November

MonthZone SSTStatus
Jan6472°FOutside
Feb6470°FOutside
Mar6874°FFishable
Apr7278°FPeak
May7682°FPeak
Junnow8084°FPeak
Jul8286°FFishable
Aug8286°FFishable
Sep8084°FPeak
Oct7682°FPeak
Nov7078°FPeak
Dec6674°FFishable
Texas Offshore & Flower Garden BanksGalveston TX · Freeport TX

Best months

April, May, June, July, August, September, October, November

MonthZone SSTStatus
Jan6472°FOutside
Feb6470°FOutside
Mar6874°FFishable
Apr7278°FPeak
May7682°FPeak
Junnow8084°FPeak
Jul8086°FPeak
Aug8086°FPeak
Sep7884°FPeak
Oct7482°FPeak
Nov7078°FPeak
Dec6674°FFishable

Conservation & regulations

ICCAT / NOAA HMS

Overfished — under ICCAT recovery plan. Catch and release standard — tag required for retention. HMS permit needed for recreational billfish targeting.

Stock assessment source →

Pull big lures and rigged ballyhoo through the warmest available water. Look for bait pods, sargassum, and temperature breaks within the 76–82°F band. Gulf of Mexico oil rigs and Mid-Atlantic canyon edges in summer.

Sources

SST threshold data is summarized from agency and research sources. Year-to-year ocean conditions vary; verify current SST imagery before each trip.

See live SST for your offshore zone.

Bield: Fish overlays NOAA CoastWatch SST imagery on your chartplotter view, highlights the temperature breaks that match blue marlin thresholds, and alerts you when your home zone hits the 7682°F window.

Start free trial →