July was the hottest month on Earth since records began, averaging 16.6 C (61.9 F), according to US scientists.
That is 0.08 degrees higher than the previous record, set in July 1998 - a significant margin in weather records.
Scientists at the US National Oceanic and Atmospheric Administration (NOAA) said in a report that they expect 2015 to be the hottest year on record.
Nine of the 10 hottest months since records began in 1880 have occurred since 2005, they NOAA report said.
Scientists say global climate change and the impacts of the El Nino weather phenomenon are behind the record temperatures.
The first seven months of 2015 have already set an all-time temperature record for the period.