Hawaii Weather for December: What Is the Forecast for the Rest of the Month?

Weather such as heavy rainfall in Hawaii has caused power outages and damage to homes and vehicles across the state.

Flooding was seen in several parts of the state, including Oahu, especially Honolulu where record rainfall levels were recorded at Honolulu Airport, the National Weather Service (NWS) said.

Precipitation levels are likely to be "above normal" in Hawaii throughout December, according to the NWS.

A state of emergency was declared across the Hawaiian islands on Monday by Hawaii Gov. David Ige and is in place until Friday.

In a statement Monday, the governor warned the state is "in danger of a disaster occurrence of heavy rains, flooding, high winds, and high surf," which are forecast to continue through Wednesday.

Periods of heavy rains and flooding are expected to cause "extensive damage" to property across the state, impacting the counties of Hawaii, Maui, Kalawao, Kauai, as well as the City and County of Honolulu, the governor said Monday.

Hawaii Weather Forecast for Next Few Days

According to the latest NWS report Wednesday, "improving weather trends are expected for most of the state from Oahu eastward to the Big Islands."

The threat of heavy rain and thunderstorms remains through the early morning hours on Wednesday due to "lingering instability" near the islands of Kauai and Niihau.

A Flood Watch is in effect in Kauai and Niihau through 6 a.m. local time Wednesday. A Flood Watch indicates conditions are favorable for flash flooding, which is life threatening, the NWS warns.

From Wednesday onward, "clouds and showers will tend to favor windward and mountain areas with drier conditions over leeward sections of each island," the federal body said.

Hawaii Weather Forecast for December 2021

According to the latest NWS monthly forecast report released on November 18, above normal precipitation is expected for the Hawaiian Islands in December, which is consistent with La Niña conditions as well as "most dynamical and statistical models," the federal body explained.

La Niña is one of two opposing climate conditions in the Pacific Ocean (the other being El Niño) that break normal trade wind patterns. The two phenomena are collectively known as the El Niño-Southern Oscillation (ENSO) cycle.

La Niña conditions are projected to continue through the winter in the Northern Hemisphere, according to the Climate Prediction Center of the National Oceanic and Atmospheric Administration (NOAA).

The NWS monthly report also said above normal temperatures are forecast for Honolulu as well as the Kahului area of Maui and the Lihue area of Kauai for December, based on the NCEP Climate Forecast System (CFS) and other climate models of the North American Multi-Model Ensemble (NMME).

"Sea surface temperature (SST) anomalies from zero degree to negative one half degree Celsius were observed over southeastern islands (Maui and Big island), while zero to positive one degree Celsius SST anomalies were observed over northwestern islands (Kauai and Oahu) during the previous week," the NWS said.

There are "Equal Chances (EC)" for above, near or below normal temperatures projected for the town of Hilo on the Big Island this month due to the "greater uncertainty among dynamical and statistical model forecasts," according to the federal body.

A beach seen empty in Honolulu, Hawaii.
A beach seen empty in Honolulu, Hawaii on December 7, 2021 following heavy rainfall across the Hawaiian islands. EUGENE TANNER/AFP via Getty Images