https://www.epa.gov/climate-indicators/climate-change-indicators-sea-surface-temperature https://www.epa.gov/climate-indicators/climate-change-indica... Take a

https://www.epa.gov/climate-indicators/climate-change-indicators-sea-surface-temperature https://www.epa.gov/climate-indicators/climate-change-indica... Take a few grains of salt. Even 1980 was long before we had great satellite data so a lot is inferred from tidal measurements in European cities