December weather forecastKahului, HI
December
Weather in December
December brings the year to a close with a cool demeanor, as temperatures fluctuate from 72.9°F (22.7°C) to 75.7°F (24.3°C). While the rainfall frequency escalates, it's quite well-balanced by the city's prolonged sunshine hours. The wind speed follows a slightly upward trend, reverberating a fresh holiday spirit across the city. Despite the reduced sea surface temperature, a relaxing stroll along the shoreline remains an inviting prospect.Temperature
With the onset of December, the average high-temperature stands at a still moderately hot 75.7°F (24.3°C), closely aligned with November's 77.7°F (25.4°C). An average nighttime temperature of 72.9°F (22.7°C) marks December.Humidity
The average relative humidity in December is 75%.Rainfall
The wettest months are March and December, with an average 0.87" (22mm) of rainfall.Ocean temperature
In Kahului, the average seawater temperature in December is 76.8°F (24.9°C).Note: Factoring in a person's dislike for cold, combined with conditions like sunshine, wind, and temperature, a dip in 76.8°F (24.9°C) waters might be satisfying. (It is worth noting that the Olympic swimming waters are maintained between 77°F (25°C) and 82.4°F (28°C).)
Daylight
With an average of 10h and 54min of daylight, December has the shortest days of the year.On the first day of December, sunrise is at 6:46 am and sunset at 5:43 pm. On the last day of the month, sunrise is at 7:02 am and sunset at 5:56 pm HST.
Sunshine
December has the least sunshine of the year, with an average of 7h of sunshine.UV index
January through June, November and December, with an average maximum UV index of 6, are months with the lowest UV index. A UV Index estimate of 6 to 7 represents a high threat to health from unsafe exposure to UV radiation for the ordinary person.Note: In December, the maximum UV index of 6 transforms into these recommendations:
Avert overexposure. Light-skinned people might experience burning in less than 20 minutes. Avoid direct Sun exposure and seek shade from 10 a.m. to 4 p.m., the period of highest UV radiation. Remember, however, that not all shade structures offer full protection. Fend off the sun's harsh rays with appropriate clothing, a wide-brim hat, and UV-protective sunglasses. Note! Reflective surfaces like sand and water heighten the UV radiation levels.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Kahului, HI
- Average high temperature in December: 75.7°F
The warmest month (with the highest average high temperature) is September (79.9°F).
The month with the lowest average high temperature is February (73.9°F).
- Average low temperature in December: 72.9°F
The month with the highest average low temperature is October (76.5°F).
The coldest months (with the lowest average low temperature) are February and March (70.7°F).
Average pressure in December
Kahului, HI
- Average pressure in December: 29.99"Hg
The month with the highest atmospheric pressure is April (30.05"Hg).
The months with the lowest atmospheric pressure are September and October (29.97"Hg).
Average wind speed in December
Kahului, HI
- Average wind speed in December: 11.7mph
The windiest month (with the highest average wind speed) is June (13.6mph).
The calmest month (with the lowest average wind speed) is January (10.4mph).
Average humidity in December
Kahului, HI
- Average humidity in December: 75%
The months with the highest relative humidity are July and August (76%).
The months with the lowest relative humidity are January and February (74%).
Average rainfall in December
Kahului, HI
- Average rainfall in December: 0.87"
The wettest months (with the highest rainfall) are March and December (0.87").
The driest month (with the least rainfall) is June (0.2").
Average rainfall days in December
Kahului, HI
- Average rainfall days in December: 9.2 days
The month with the highest number of rainy days is March (11.9 days).
The month with the least rainy days is June (6.6 days).
Average sea temperature in December
Kahului, HI
- Average sea temperature in December: 76.8°F
The best month for swimming (with the highest average sea temperature) is September (80°F).
The coldest month (with the lowest average sea temperature) is March (75.6°F).
Average daylight in December /
Average sunshine in December
Kahului, HI
- Average daylight in December: 10h and 54min
The month with the longest days is June (Average daylight: 13h and 24min).
The month with the shortest days is December (Average daylight: 10h and 54min).
- Average sunshine in December: 7h and 0min
The month with the most sunshine is June (Average sunshine: 11h and 30min).
The month with the least sunshine is December (Average sunshine: 7h and 0min).
Average sunshine days in December
Kahului, HI
- Average sunshine days in December: 17.7 days
The month with the most sunshine days is June (19.9 days).
The month with the least sunshine days is March (15.2 days).
Average UV index in December
Kahului, HI
- Average UV index in December: 6
The months with the highest UV index are July, August, September and October (UV index 7).
The months with the lowest UV index are January, February, March, April, May, June, November and December (UV index 6).
Average cloud cover in December
Kahului, HI
- Average cloud cover in December: 24
The month with the most cloud cover is March (Cloud cover 30).
The months with the least cloud cover are June and September (Cloud cover 21).
Average visibility in December
Kahului, HI
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
