Pictures showed fissures at the base of the volcano’s crater generating glowing lava flows for the first time after a two-month pause.
The Hawaii Emergency Management Agency said the eruption “does not pose a lava threat to communities" though volcanic particles and gases may create breathing problems for people exposed.
Officials said gases released by the eruption will cause volcanic smog downwind of Kilauea, located in the southeast of Hawaii, which people should try to avoid.
The volcano’s alert level was raised to warning status as scientists evaluate the eruption and associated risks.
In June, Kilauea erupted for several weeks, displaying fountains of red lava without threatening any communities or structures.
Crowds of people flocked to the Big Island’s Hawaii Volcanoes National Park, which offered safe views of the lava.
Kilauea, Hawaii’s youngest volcano, formed underwater around 280,000 years ago.
It erupted almost continuously from 1983 to 2018, and again from 2020 onward.
A 2018 Kilauea eruption destroyed more than 700 homes.