Alkaline eruptions in Hualalai have generally been much less explosive than those at neighboring Kohala and Mauna Kea volcanoes.
However, in 1929 an intense earthquake swarm hit Hualalai for a period of one month, which has been interpreted as due to an intrusion of magma near the surface, without a superficial eruption. No magma-related seismicity or soil deformation has been detected recently in Hualalai, making it difficult to say if and when the next eruption could occur. This also presents a clear danger to the surrounding communities; for example, in the event of an eruption similar to that of 1801, Kailua-Kona, which is 15 miles (24 km) from the summit of the volcano, could be completely covered in a matter of hours. To be considered active, a volcano will have erupted at least once in the past 10,000 years, and there is still enough seismic activity below the surface to suggest that another eruption may occur in the next 1000 years or less.
Although 200 years have passed since the last Hualalai eruption, it is almost certain that it will erupt again. For residents of the Kona area, keep in mind that Hualalai hasn't erupted since 1801; Mauna Loa is considered active but hasn't erupted since 1984.Lava flows represent by far the greatest danger in a possible future Hualalai eruption, because although explosive pyroclastic eruptions have occurred during the Holocene epoch (the past 10,000 years), they are relatively rare and cover only limited parts of the volcano. Due to this and the fact that more than 200 years have passed since its last eruption, Hualalai volcano is considered a potentially dangerous volcano on the island of Hawaii that is delayed for an eruption. For example, its summit is only 15 km from the city of Kailua-Kona and a flow as voluminous as the eruption of 1800 could cover that distance in a few hours.
Most of the flows of the Kilauea eruption have been southbound from the Pu'u 'ō'ō splash cone at the top of Kilauea.
