Sea surface temperature guide
Bigeye Tuna sea surface temperature guide.
- Thunnus obesus
- Tuna
- Agency-reported threshold data
Bigeye tuna live deeper than any other commonly-targeted tuna species — they spend their days at 600 to 1500 feet. Surface SST is less predictive than for yellowfin or mahi. Use SST imagery to identify productive canyons, then fish the structure at depth.
SST threshold gauge
The temperature ranges that matter.
The water temperature ranges that determine where bigeye tuna hold and feed. Hard thresholds (dashed lines) are values outside which fish actively depart or become inactive.
Depth profile & SST reliability
Typical depth
200–1500 feet
SST as locator
Low — fish location is bathymetry-driven
Bigeye live deep — 600 to 1500 feet during the day, rising at night to feed. Surface SST is a poor predictor of bigeye location. Daytime trolling for bigeye targets the thermocline depth, not the surface temperature.
Current systems & structure
Bigeye associate with deep canyon structure and warm core eddies but at depth, not at the surface. Surface SST tells you which canyons might be productive but not whether the fish are there.
Best zones now
Where bigeye tuna are in range — August.
Zones where typical August SST falls in bigeye tuna's preferred range.
Zone-by-zone calendar
Overlap charts by zone.
For each zone where bigeye tuna 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
Best months
May, June, July, August, September, October
| Month | Zone SST | Status |
|---|---|---|
| Jan | 44–52°F | Fishable |
| Feb | 44–50°F | Outside |
| Mar | 44–52°F | Fishable |
| Apr | 46–56°F | Fishable |
| May | 54–64°F | Peak |
| Jun | 62–72°F | Peak |
| Jul | 68–78°F | Peak |
| Augnow | 70–80°F | Peak |
| Sep | 66–74°F | Peak |
| Oct | 58–66°F | Peak |
| Nov | 52–60°F | Fishable |
| Dec | 46–54°F | Fishable |
Best months
May, June, July, September, October, November
| Month | Zone SST | Status |
|---|---|---|
| Jan | 46–54°F | Fishable |
| Feb | 46–54°F | Fishable |
| Mar | 48–56°F | Fishable |
| Apr | 50–60°F | Fishable |
| May | 56–66°F | Peak |
| Jun | 64–74°F | Peak |
| Jul | 70–80°F | Peak |
| Augnow | 72–82°F | Fishable |
| Sep | 68–76°F | Peak |
| Oct | 60–68°F | Peak |
| Nov | 54–62°F | Peak |
| Dec | 48–56°F | Fishable |
Best months
April, May, June, September, October, November
| Month | Zone SST | Status |
|---|---|---|
| Jan | 48–58°F | Fishable |
| Feb | 48–56°F | Fishable |
| Mar | 50–60°F | Fishable |
| Apr | 54–64°F | Peak |
| May | 60–70°F | Peak |
| Jun | 68–78°F | Peak |
| Jul | 72–82°F | Fishable |
| Augnow | 74–84°F | Outside |
| Sep | 70–80°F | Peak |
| Oct | 64–72°F | Peak |
| Nov | 56–64°F | Peak |
| Dec | 50–60°F | Fishable |
Gulf of Mexico
Best months
January, February, March, November, December
| Month | Zone SST | Status |
|---|---|---|
| Jan | 64–72°F | Peak |
| Feb | 64–70°F | Peak |
| Mar | 68–74°F | Peak |
| Apr | 72–78°F | Fishable |
| May | 76–82°F | Outside |
| Jun | 80–84°F | Outside |
| Jul | 82–86°F | Outside |
| Augnow | 82–86°F | Outside |
| Sep | 80–84°F | Outside |
| Oct | 76–82°F | Outside |
| Nov | 70–78°F | Peak |
| Dec | 66–74°F | Peak |
Conservation & regulations
ICCAT / NOAA
Overfished — under rebuilding plan in Atlantic per ICCAT. ICCAT-managed Atlantic stock under rebuilding plan. HMS permit required. Strict bag and size limits. Verify current rules before keeping fish.
Stock assessment source →Bigeye fishing is canyon-edge fishing at depth. Troll deep-running plugs along the 100-fathom line at sunrise and sunset. SST charts help identify which canyons are eddy-influenced; use bathymetry to find the structure.
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 bigeye tuna thresholds, and alerts you when your home zone hits the 59–72°F window.
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