Due to climate change, the average temperature of deep water (more than 300 metres or 980 feet deep) increased from 4.4 °C (39.9 °F) in 1963 to 5.5 °C (41.9 °F) in 2016 (an increase of 1.1 °C or 2.0 °F in 53 years), while the average temperature of surface water (five metres or 16 feet deep) increased from 10.9 °C (51.6 °F) in 1970 to 12.9 °C (55.2 °F) in 2016 (up 2 °C or 3.6 °F in 46 years).[11]