The recording is being confirmed by the U.S National Weather Service, Sunday’s reading was recorded in Furnace Creek in Death Valley.
It comes amid a heatwave on the U.S’s west coast, where temperatures are forecast to hit further this week.
The scorching conditions have resulted to two days of blackouts in California, after a power plant malfunctioned on Saturday.
Before this, the hottest temperature reliably recorded on Earth was 129.2F (54C) – also in Death Valley in 2013.
A higher reading of 134F, or 56.6C a century earlier, also in Death Valley, is debated. It is believed by some modern weather experts to have been wrong, including several other searing temperatures recorded that summer.
According to a 2016 analysis from weather historian Christopher Burt, other temperatures in the region recorded in 1913 do not confirm the Death Valley reading.
Another record temperature for the planet – 131F, or 55C – was recorded in Tunisia in 1931, but Mr Burt said this reading, as well as others recorded in Africa during the colonial era, had “serious credibility issues”.
The current heatwave goes from Arizona in the south-west, up the coast to Washington state in the north-west.
It is anticipated to rise its peak on Monday and Tuesday, before temperatures start to decrease later in the week. Nevertheless, the hot heat will carry on for at least another 10 days.
As temperatures increased in California, a large “firenado” was seen on Saturday in Lassen County.
California’s Independent System Operator (CISO), which manages the state’s power, has announced a Stage 3 Emergency, meaning “when demand [for electricity] begins to outpace supply”.
Because so much of the region’s power depend on solar and wind energy, and because people use their electricity for air conditioning, during heatwaves the power grid becomes drawn and is at danger of completely malfunctioning.
In order to handle the state’s demand for power and avoid a total shutdown, officials are using scheduled rolling blackouts to manage and conserve energy.