WASHINGTON — Summer Arctic sea ice shrank to its fourth-lowest level on record this month, dispelling faint hopes of a recovery, federal scientists said.

The National Snow and Ice Data Center announced Tuesday that the Arctic hit its summer minimum last week with 1.7 million square miles of sea ice, down 240,000 square miles from 2014. That’s a difference the size of California, New York and Maryland combined.

“The ice is decreasing over time, which you would expect because the Arctic is warming,” data center scientist Julienne Stroeve said.

Summer minimum sea ice has shrunk since satellites started measuring in 1979. It reached a peak of 2.91 million square miles in 1980 and hit an all-time low of 1.3 million square miles in 2012. It went back up to 1.95 in 2013 and hovered near there in 2014.