Year 2011, in the continental United States has been indicated as the country's hottest year as of 1895 posit government scientists.
According to the BBC, the National Oceanic and Atmospheric Administration (NOAA) said that the US had broken its record for the hottest six months.
Agency's weather experts said that climate changes were playing a major role in the changes in the temperatures.
A recent 11-day heat wave in the US claimed at least 46 lives, the report said.
Forecasters said that hot weather could now affect the western US and Canada, where Ontario has been experiencing record-breaking temperatures.ccording to the NOAA's National Climatic Data Center, more than 170 all-time hot weather records were broken, or tied, during the second half of June.
Jake Crouch, a scientist at the National Climatic Data Center, said: "It's hard to pinpoint climate change as the driving factor, but it appears that it is playing a role.
"What's going on for 2012 is exactly what we would expect from climate change," he added.
On Saturday temperatures reached 105F in Washington DC, just short of the hottest ever recorded in the city.