Annual Precipitation on the Island of Hawaii between 1890 and 1977

Abstract

Long-term annual precipitation records from 31 stations on the southeast and windward sides of the island of Hawaii were analyzed by a simple linear regression technique for possible significant trends during the approximate period 1900-1977. Records from stations along the windward side of the island showed a general downward trend and along the southeast side of the island a general upward trend. An explanation for these trends has not been found; however, a shift in tradewind direction has been suggested as a possible cause. Wind direction records are not complete enough to establish a relationship between the two trends. The decrease in annual precipitation around the Waimea area represents a significant effect on water resources of the area.