Temperatures peaked at 32.22 Celsius (90F) on 4 July at an airport in Anchorage, the state's largest city.
National Weather Service meteorologist Bob Clay said Anchorage's average high temperature for US Independence Day is 23.89C (75F).
Other local records were set across southern Alaska and come after five weeks of above average temperatures.
Shawn King, who has lived his entire life in Anchorage, said he had never seen a stretch of similar hot weather.
The #4thofjuly2019 was one for the books. Several ALL-TIME high temperature records were set at official observation sites throughout Southern #Alaska. But that's not all...there were more daily temperature records set too! #AKwx #ItsHotInAlaska pic.twitter.com/GxcdUaD9ld
— NWS Anchorage (@NWSAnchorage)
The 31-year-old used the occasion to take his daughter, Tessa, fishing for the first time on the dock of Jewel Lake.
She insisted on going barefoot.
"It's too hot for shoes," the four-year-old said.
While tourists have been caught out after being told to expect cooler temperatures. Judy Zickmund, who arrived in Anchorage on a cruise, said: "We didn't pack clothes for it".
Three other Alaska locations, Kenai, Palmer and King Salmon, set or tied all-time high temperature records.
However the statewide record of 37.8C (100F), was set at Fort Yukon in the state's north east region over a century ago.
Meteorologists say a "heat dome" over the state is responsible for the latest heatwave, and is set to continue for days as the system moves north.
Rick Thoman, a climate specialist at the University of Alaska said these exceptionally warm weather events will only become more frequent because of the loss of sea ice and warming in the Arctic Ocean.
"These kinds of extreme weather events become much more likely in a warming world," Thoman said. "Surface temperatures are above normal everywhere around Alaska. The entire Gulf of Alaska, in the Bering Sea, in the Chukchi Sea south of the ice edge, exceptionally warm waters, warmest on record, and of course record-low sea ice extent for this time of year off the north and northwest coasts of the state."