What’s the weather like in hawaii in december – Whats the weather like in Hawaii in December? This question sparks curiosity and invites you to embark on a journey to explore the beautiful state’s climate during one of its peak months. Located in the Pacific Ocean, Hawaii is known for its tropical paradise and unique weather patterns shaped by the trade winds, North Pacific High, and the state’s geography.
December marks the beginning of winter in the Northern Hemisphere, but in Hawaii, it’s the start of a comfortable and sunny season. The weather in Hawaii in December is generally pleasant, with average temperatures ranging from the mid-70s to mid-80s Fahrenheit (23-30°C) across the islands. However, it’s not uncommon for some parts of the state to experience cooler temperatures, especially in the mornings and evenings.
Weather Patterns in Hawaii During December: What’s The Weather Like In Hawaii In December
Hawaii’s weather during December is typically mild and pleasant, with temperatures ranging from the mid-70s to the mid-80s Fahrenheit (23-30°C) throughout the archipelago. The islands experience a relatively dry winter season, with most rainfall occurring during the months of November to March.
The North Pacific High, a large anticyclonic circulation system, plays a significant role in shaping the climate in Hawaii. This high-pressure system, also known as the Aleutian Low, dominates the North Pacific Ocean and influences the trade winds, which in turn affect the weather conditions in Hawaii. The trade winds, which originate from the northeast, bring warm, moist air from the tropics towards the Hawaiian Islands, contributing to their mild and stable temperatures.
Anticyclonic and Cyclonic Systems Influence the Weather in Hawaii
The North Pacific High and the trade winds create a favorable environment for the formation of anticyclonic systems over Hawaii. These high-pressure systems are characterized by descending air that cools and condenses, resulting in the formation of clouds and precipitation. The anticyclonic systems are more pronounced during the winter months, resulting in increased cloud cover and rainfall.
Frequency and Duration of Rainy Days
Although Hawaii experiences a relatively dry winter season, some parts of the archipelago receive more rainfall than others. The windward coasts of the islands, particularly Kauai, Oahu, and Hawaii Island, receive an average of 8-12 inches (20-30 cm) of rainfall during December, while the leeward coasts receive significantly less. The drier leeward coasts experience an average of 2-4 inches (5-10 cm) of rainfall, while the islands’ interior and mountainous regions receive an average of 12-20 inches (30-50 cm) or more.
Trade Winds Influence Climate in Hawaii During December
The trade winds play a crucial role in shaping Hawaii’s climate during December. The winds, which originate from the northeast, bring warm, moist air from the tropics towards the Hawaiian Islands. This warm air fuels the trade winds, creating a self-sustaining loop of moisture and temperature. The trade winds also influence the formation of clouds and precipitation in the islands, making December a great time to experience Hawaii’s tropical climate without the sweltering heat of the summer months.
Climate Patterns in Different Islands
Each island in Hawaii experiences unique climate patterns during December. The windward coasts of Kauai and Oahu typically receive the most rainfall, with an average of 10-15 inches (25-38 cm). In contrast, the leeward coasts of Lanai and Maui experience relatively dry conditions, with an average rainfall of 2-4 inches (5-10 cm).
Climatological Normals for Hawaii During December
According to the National Centers for Environmental Information (NCEI), the climatological normals for Hawaii during December are:
– Temperature: 76-80°F (24-27°C) in the mornings and 80-84°F (27-29°C) in the afternoons
– Rainfall: 8-12 inches (20-30 cm) in the windward coasts and 2-4 inches (5-10 cm) in the leeward coasts
– Sunshine hours: 80-90% of possible sunshine hours throughout the day
Temperature Variations Across the Islands
December is a great time to visit Hawaii, with mild temperatures and plenty of sunshine. The islands’ temperatures can fluctuate depending on the location and elevation, but overall, it’s a wonderful month to explore the beautiful landscapes of Hawaii.
Temperature-wise, each island has its unique characteristics. Honolulu, the capital city of Oahu, is generally warmer than the northern islands. Maui and Kauai have a slightly cooler climate due to their high elevations, while the Big Island is known for its varied temperatures, ranging from tropical to subtropical zones.
Temperature Ranges Across the Islands
The average temperatures in December for each island are as follows:
- Honolulu (Oahu): Highs around 78°F (25°C), lows around 65°F (18°C)
- Maui: Highs around 75°F (24°C), lows around 60°F (16°C)
- Kauai: Highs around 72°F (22°C), lows around 55°F (13°C)
- Big Island: Highs around 75°F (24°C) in the Hilo region, lows around 60°F (16°C); in the Kona region, highs around 80°F (27°C), lows around 65°F (18°C)
Notice that the temperatures are relatively consistent across the islands, with slight variations depending on the elevation and proximity to the ocean. The Big Island’s temperature ranges are the most notable, with the Hilo region being cooler and the Kona region being warmer.
Temperature Fluctuations Between Northern and Southern Islands
A significant difference in temperature can be observed between the northern and southern islands. The northern islands, including Kauai and part of the Big Island, tend to be cooler due to their exposure to the northeast trade winds. These winds bring cooler air from the north, resulting in a cooler climate.
On the other hand, the southern islands, such as Maui and Oahu, tend to be warmer due to their proximity to the equator and their exposure to the southwest trade winds. These winds bring warmer air from the south, resulting in a warmer climate.
Temperature Variations and Orographic Clouds
The temperature variations across the islands play a significant role in the formation of orographic clouds. Orographic clouds are formed when moist air is forced to rise over a mountain or hill, resulting in the formation of clouds and precipitation.
In Hawaii, the temperature variations contribute to the formation of orographic clouds in several ways. For instance, the cool air from the north tends to condense and form clouds in the northern islands, while the warm air from the south tends to evaporate and form clouds in the southern islands.
The combination of temperature variations and orographic conditions creates a unique microclimate in each island, leading to a diverse range of weather patterns and precipitation. This diversity is one of the reasons why Hawaii is known for its varied landscapes and unique climate.
Precipitation and Rainfall in Hawaii
December marks the beginning of the wet season in Hawaii, with the majority of the islands receiving significantly more rainfall than the dry summer months. The state’s tropical location and unique geography create a complex precipitation pattern, with rain showers falling primarily on the windward coasts and mountainous regions.
Monthly Rainfall Averages for Each Island in December
Hawaii’s eight main islands vary in terms of their monthly rainfall averages during December. Here’s a general overview of the rainfall patterns across the islands:
- Oahu: With an average of around 4.5 inches (114 mm), Oahu’s rainfall in December is relatively moderate, with most of it falling on the windward coast.
- Maui: Maui experiences an average of around 5.4 inches (137 mm) in December, with the southern coast receiving more rainfall than the northern coast.
- Kauai: Kauai is often considered one of the wettest islands in the world, with an average of around 8.5 inches (216 mm) in December. The island’s mountainous terrain creates a pronounced orographic effect, leading to heavy rainfall in the mountainous regions.
- Hawaii Island: The Big Island receives an average of around 5.5 inches (140 mm) in December, with the Kona coast on the leeward side experiencing significantly less rainfall than the Hilo coast on the windward side.
- Lanai: With an average of around 2.5 inches (64 mm), Lanai is one of the driest islands in Hawaii, receiving minimal rainfall throughout the year.
- Molokai: Molokai averages around 4.5 inches (114 mm) in December, with most of it falling on the windward coast.
- Niihau: Due to its remote location and island ecosystem, Niihau’s rainfall patterns are not as well-documented as other islands, but it is believed to receive an average of around 3-4 inches (76-102 mm) in December.
- Kahoolawe: This small, uninhabited island receives minimal rainfall, with an average of around 2 inches (51 mm) in December.
Significant Rainfall Events in Hawaii’s History During December
Hawaii has experienced several significant rainfall events in December, with some of the most notable ones including:
- The December 1948 storm on Oahu: Heavy rainfall led to severe flooding in the Nuuanu Valley, resulting in 30 fatalities and over 1 billion dollars in damage.
- The 1950-1951 drought and subsequent 1966-1967 storms: The prolonged drought on the Big Island ended with the 1966-1967 El Nino event, which brought heavy rainfall and floods to the island, causing widespread damage and loss of life.
- The 1979 Hawaiian Rainfall Floods: Heavy rainfall across several islands resulted in flash flooding, landslides, and an estimated 1 billion dollars in damage.
- The 2020 COVID-19 pandemic-related storms: The arrival of Tropical Storm Douglas in August 2020, and the subsequent passage of a low-pressure system in October 2020, brought heavy rainfall to the islands, exacerbating the pandemic-related economic challenges facing the state.
Effects of Heavy Rainfall on Hawaii’s Infrastructure and Ecosystems
The impact of heavy rainfall on Hawaii’s infrastructure and ecosystems can be severe, with some of the most notable effects including:
- Floods and landslides: Heavy rainfall can lead to flash flooding and landslides, damaging buildings, roads, and bridges, and putting lives at risk.
- Disruption of services and transportation: Flooding and landslides can disrupt essential services, such as power, water supply, and communication, and make roads impassable, affecting residents and tourists alike.
- Deterioration of ecosystems: Heavy rainfall can alter the delicate balance of Hawaii’s ecosystems, leading to changes in species distribution and potentially threatening the long-term sustainability of the islands’ unique biodiversity.
Sunshine Hours and Daylight Saving
Hawaii is the most geographically isolated population center in the world, and its unique location creates a distinct pattern of daylight throughout the year. In December, the state observes standard time, which means there is no daylight saving time (DST) adjustment.
The duration of daylight in Hawaii during December ranges from 10 hours and 35 minutes in Honolulu to 11 hours and 20 minutes in Kauai, with the sun rising around 6:30 am and setting around 6:00 pm local time. This variation is due to the state’s unique geography, with islands to the north receiving more direct sunlight and experiencing longer days than those to the south.
Average Sunshine Hours Across Regions
While the duration of daylight varies across the islands, the overall amount of sunshine remains relatively consistent. The southernmost islands, such as Hawaii Island, receive slightly less sunshine due to their orientation and the trade winds that bring clouds from the ocean. In contrast, the northernmost islands, including Kauai and Maui, receive more direct sunlight and experience more sunny days.
| Region | Average Sunshine Hours (December) | Number of Sunny Days (December) |
| — | — | — |
| Honolulu | 9-10 hours | 20-22 days |
| Maui | 9-11 hours | 22-24 days |
| Kauai | 9-12 hours | 24-26 days |
| Hawaii Island | 8-10 hours | 18-20 days |
Sunny Days in Different Regions
Here are the average numbers of sunny days in various regions of Hawaii during December:
- Honolulu: Enjoy up to 22 sunny days in December, with the sunniest days usually occurring in the middle of the month. Expect average high temperatures around 78°F (25°C) and average low temperatures around 67°F (19°C).
- Maui: Expect up to 24 sunny days in December, with the sunniest days often occurring towards the end of the month. Average high temperatures range from 78°F (25°C) to 84°F (29°C), while average low temperatures range from 66°F (19°C) to 72°F (22°C).
- Kauai: Kauai is known for its lush landscapes and tropical climate, with an average of 24 to 26 sunny days in December. Expect average high temperatures between 75°F (24°C) and 82°F (28°C), while average low temperatures range from 63°F (17°C) to 69°F (21°C).
Sunshine hours are influenced by atmospheric conditions, such as cloud cover, humidity, and air temperature. However, Hawaii’s tropical climate ensures a relatively consistent amount of sunshine throughout the year.
Wind Patterns and Ocean Swells
In December, Hawaii experiences a mix of trade winds and the onset of the winter months’ stormier weather patterns, affecting its wind and ocean swell conditions. Trade winds, which typically blow from the northeast to east, play a significant role in shaping Hawaii’s shoreline and coastal ecosystems. The consistent wind directions influence the state’s coastal topography, erosion patterns, and marine life habitats.
Dominant Wind Directions and Speeds
The trade winds are the primary wind direction in December, with wind speeds averaging 15-25 mph (24-40 km/h) statewide. There is also a notable increase in northeasterly winds from mid-December onwards, which can bring stronger winds and increased ocean swells. These wind patterns are essential to understanding the ocean swell conditions off Hawaii’s coastlines.
Impact on Shoreline and Coastal Ecosystems
The consistent trade winds contribute to the formation of coral reefs, which provide vital habitats for many marine species. The trade winds also influence the growth of seagrass beds, which help to stabilize the coastline and provide shelter for juvenile fish. In contrast, the stronger northeasterly winds can cause erosion and transport sediments, leading to changes in the coastline’s shape and composition.
The swell patterns in the Pacific Ocean during December show a noticeable increase in northeasterly swells from late November to mid-January, peaking in December with average wave heights of 6-8 feet (2-2.5 meters). These swells originate from low-pressure systems in the central Pacific and are influenced by the trade winds and other atmospheric conditions. This swell pattern can cause increased wave action, beach erosion, and changes in ocean currents along Hawaii’s coastlines.
Regional Weather Forecasts and Warnings
In Hawaii, accurate and timely weather forecasts and warnings play a vital role in maintaining public safety and minimizing disruptions to daily life. To achieve this, numerous sources provide weather-related information and alerts to the residents and visitors.
Sources of Weather Forecasts and Warnings in Hawaii
The National Weather Service (NWS), Hawaii Department of Transportation, and various local news organizations serve as key sources of weather forecasts and warnings in Hawaii. The NWS issues weather forecasts, warnings, and advisories for the state, which are disseminated through various channels, including social media, text messaging, and broadcast media. Additionally, local news organizations, such as Hawaii News Now and KHON2, provide regular updates on weather conditions and forecasts.
Examples of Successful Weather-Related Warnings and Alerts, What’s the weather like in hawaii in december
Several notable examples of successful weather-related warnings and alerts in Hawaii include:
- Hurricane Lane in 2018: The NWS issued timely warnings and advisories, allowing authorities to evacuate vulnerable areas, minimizing damage and loss of life. Residents and visitors followed warnings, taking necessary precautions to ensure their safety.
- Mauna Loa eruption in 2022: The US Geological Survey (USGS) and NWS collaborated to issue warnings and updates on the volcanic eruption, providing critical information to authorities and the public, enabling them to take necessary precautions.
Accuracy of Weather Forecasting Models Used in Hawaii
The NWS and other weather forecasting agencies utilize various models to predict weather patterns in Hawaii. The Global Forecast System (GFS) and European Centre for Medium-Range Weather Forecasts (ECMWF) models are two prominent models used to forecast weather conditions in Hawaii. These models are used in conjunction with radar and satellite data to provide accurate and timely forecasts. While no forecasting model is 100% accurate, these models have been shown to be reliable and effective in predicting weather patterns in Hawaii.
Comparison of Forecasting Models
Comparative studies suggest that the ECMWF model has been more accurate in predicting weather patterns in Hawaii, particularly for longer-range forecasts. Conversely, the GFS model has been more accurate for shorter-range forecasts. However, both models are reliable tools in predicting weather conditions in Hawaii, and their use has improved forecast accuracy over the years.
Road Closure and Aviation Forecasts
Hawaii Department of Transportation and the Federal Aviation Administration (FAA) issue separate forecasts and warnings for road conditions and aviation. These forecasts are crucial for travelers and residents to avoid hazardous conditions and minimize disruptions to air travel.
Special Weather Advisories and Warnings
In addition to regular weather forecasts, the NWS issues special weather advisories and warnings for specific weather conditions, such as high surf, flash flooding, and wildfires.
Conclusive Thoughts
In summary, the weather in Hawaii in December is a unique blend of tropical and subtropical influences, creating a comfortable and sunny climate for visitors and residents alike. With this knowledge, you can plan your trip to Hawaii or make the most of your stay during this wonderful time of the year.
FAQ Insights
Q: What are the average temperatures in Honolulu, Maui, Kauai, and the Big Island during December?
A: The average temperatures in Honolulu, Maui, Kauai, and the Big Island during December range from the mid-70s to mid-80s Fahrenheit (23-30°C).
Q: How does the North Pacific High influence the weather in Hawaii during December?
A: The North Pacific High provides a stable and high-pressure system that dominates the weather in Hawaii during December, bringing stable and dry air to the state.
Q: What are the most significant rain events in Hawaii’s history during December?
A: While Hawaii can experience significant rain events during December, there are no notable hurricanes or typhoons that have impacted the state during this month in recent history.
Q: How does the trade wind affect Hawaii’s shoreline and coastal ecosystems?
A: The trade wind plays a crucial role in shaping Hawaii’s shoreline and coastal ecosystems, bringing warm and moist air that contributes to the state’s tropical climate and marine life.
