The summer of 2021 was one for the history books.

Three months among the hottest on record, including a chart-topping July, made this summer the second hottest in the Northern Hemisphere since record keeping began more than 140 years ago, the National Oceanic and Atmospheric Administration announced Tuesday.

Globally, NOAA said, August had its sixth highest temperatures on record. That, combined with the Northern Hemisphere’s hottest July and second-hottest June on the books, led to the globe’s fourth warmest summer ever recorded.

Scientists refer to June through August as the meteorological summer. This is distinct from the astronomical summer, which runs from the summer solstices on June 21 to the autumnal equinox on Sept. 22.

There have been significant peculiarities in the global climate this year, NOAA said, including major storms in the last few months. In late August, Hurricane Ida rolled over Louisiana as a powerful Category 4 storm before drenching the East Coast, while earlier this year Hurricane Grace, the season’s first hurricane, was one of the strongest to ever make landfall in Eastern Mexico.

Boston experienced its warmest summer on record this year, a trend echoed across New England, where temperatures have recently reached historic heights.

The Northeast has seen the worst heat increases of any area in the United States, according to Michael Rawlins of the Climate System Research Center at the University of Massachusetts Amherst.

But the Northeast is not alone in feeling the heat. The contiguous U.S. topped 74 degrees Fahrenheit on average this summer, the warmest on record.

Thus far, 2021 is the sixth hottest year on record, and NOAA believes it will end up among the 10 warmest years recorded.

Globally, nine of the 10 warmest meteorological summers have occurred since 2010, NOAA says.

Massachusetts had the second-warmest August and warmest minimum temperatures on record this summer.

Also, 2021 has been warmer and wetter: Boston had the warmest and 3rd-wettest summer on record, Worcester had the 4th-wettest summer, and 11th-warmest on record

Climate data from the last 125 years suggests the Northeast experienced the most significant temperature increases.