Scientists have kept records of global temperatures since the 1880s, and this May has tied the two hottest months of May on record (1998 and 2005). Many areas of the world, including parts of Siberia and Russia, parts of Australia and north and east Europe experienced higher than usual temperatures, according to NOAA.

Global temperatures in the 20th century averaged 58.6 degrees Fahrenheit. May’s record this year was 59.79 degrees Fahrenheit, the 339th consecutive month with a temperature above the 20th century average, suggesting a slow warming of the Earth’s atmosphere.