The year 2014 was the world’s warmest on record, despite relatively cool temperatures across parts of North America, two federal agencies responsible for monitoring global climate trends said Friday.

Climate experts from the National Aeronautics and Space Administration and the National Oceanic and Atmospheric Administration, working independently, calculated that the globally averaged temperature over land and ocean surfaces for 2014 was 58.24 degrees Fahrenheit, 1.24°F (0.69°C) above the 20th century average, the highest...