Although Hurricane Lane remained west of the Big Island, tremendous amounts of rain battered eastern areas of the island from August 22 to 26. Accumulations were greatest along the eastern slopes of Mauna Loa with a maximum of at Kahūnā Falls in Akaka Falls State Park, as measured by a private weather station. This made Lane the wettest tropical cyclone on record in the state of Hawaii, surpassing the previous peak of during Hurricane Hiki in 1950. Lane's peak rainfall total was also the second-highest recorded from a tropical cyclone within the United States, surpassed only by Hurricane Harvey in the preceding year. Hilo saw its wettest three-day period on record with of precipitation observed; fell on August 24 alone, marking the fifth-wettest day in the city's recorded history. Additional storm-total accumulations include at Waiākea-Uka, at the USGS Saddle Quarry station, and at the Waiakea Experiment Station in Hilo. Precipitation in the Hilo Region was likely amplified by the terrain on the windward side of the island, the position of rainbands, the environment generated by the cyclone, and katabatic winds. Along the erupting Kīlauea volcano, the rain led to minor rockfalls. The porous nature of volcanic rock and land in the Puna District served to mitigate the amount of runoff.
