January 31 – Lieutenant governor Shan Tsutsui abruptly resigns to accept a job with a political strategy firm. Attorney general Doug Chin is named his successor after Senate President Ron Kouchi and House Speaker Scott Saiki decline to accept the position.
April 13 – 2018 Hawaiʻi floods: Heavy rainfall on the islands of Kauaʻi and Oʻahu causes widespread flash flooding and landslides, resulting in $125million in property damage.
May 3 –
2018 lower Puna eruption: Kīlauea on Hawaiʻi Island begins erupting in the residential neighborhood of Leilani Estates. Over 700 homes are destroyed by the end of the eruption on September5. The end of the eruption in Puna is also the first time in 35years that Kīlauea is not erupting.
August 22 – Hurricane Lane causes heavy rainfall and widespread flooding across the entire state, and contributed to a wildfire in Kauaula Valley on Maui.
September 12 – Hurricane Olivia becomes the first named storm in recorded history to make landfall on the island of Maui.
October 8 – 2,700union members of UNITE HERE Local 5 employed at four hotels on Oʻahu and one hotel on Maui go on strike as part of the nationwide 2018 Marriott Hotels strike. The strike in Hawaiʻi ends after union members ratify a new contract on November27.
