Hilo weather in December

In December, Hilo sees average daytime highs of 73°F and overnight lows near 68°F, with 7.9 in of rain across 22.2 wet days and about 10.8 hours of daylight. It is the 8th-warmest and 2nd-wettest month of the year here.

Day-to-day highs hold fairly steady near 73°F through the month. The sky is clear or mostly clear about 30% of the time in December, and the air most often feels humid.

Daylight stretches from about 10 h 54 min at the start of December to 10 h 48 min by month's end. Set against the rest of the year, December is Hilo's 7th-clearest and 4th-windiest month. For the whole year in context, see Hilo's year-round climate.

Daytime high
73°
8th warmest
Overnight low
68°
5th coldest
Rainfall
7.9 in
22.2 wet days
Daylight
10 h 48 min
6:52 AM – 5:41 PM
Cloud cover
56%
7th clearest
Wind
7 mph
4th windiest
Solar energy
4.17 kWh/m²
Travel score
5.1
out of 10

Hilo is human settlement and census-designated place in Hawaii, United States.

Density
287/km²
people per km²

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 73°F through the month.

A typical December day in Hilo reaches about 73°F in the afternoon and slips back to 68°F overnight — a 5°F spread between the day's warmth and the night's chill. On most days the high lands between 71°F and 76°F. Set against its neighbours, December runs about 1°F cooler than November and on par with January.

60°65°70°75°80°151015202531
Avg high (°F)Avg low (°F)
17469
27469
37469
47469
57469
67469
77469
87469
97469
107369
117368
127368
137368
147368
157368
167368
177368
187368
197368
207368
217368
227368
237368
247368
257368
267368
277368
287368
297368
307368
317368

Hilo weather by month

How December compares with the rest of the year at a glance. December is the 8th-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan73° / 67°5.816.810.96.0
Feb72° / 67°6.617.211.35.5
Mar72° / 67°9.123.511.94.7
Apr73° / 68°7.124.812.44.5
May74° / 69°5.723.712.94.9
Jun75° / 70°4.724.113.24.8
Jul76° / 71°5.725.813.14.6
Aug77° / 72°6.725.612.74.6
Sep77° / 72°4.52212.15.1
Oct77° / 71°5.42311.55.0
Nov75° / 70°7.523.211.14.8
Dec73° / 68°7.922.210.85.1

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 30% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 29% of December, with mostly cloudy or overcast conditions the remaining 41%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14753
24852
34951
45050
55050
65149
75248
85248
95446
105545
115644
125644
135842
145842
155941
165941
176040
186040
196238
206238
216337
226436
236436
246535
256535
266733
276733
286832
296931
306931
316931

Chance of precipitation in December

Any precipitation

Hilo gets around 7.9 in of rain over 22.2 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 71% and peaks near 76% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%80%151015202531
Rain chance (%)
176
276
375
475
574
674
774
874
973
1073
1173
1273
1373
1473
1573
1673
1773
1873
1972
2072
2171
2271
2370
2469
2568
2667
2765
2864
2963
3061
3160

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

Most of December feels humid — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, December lands in the humid band about 49% of days. Sticky, muggy-or-worse air turns up on roughly 44% of them.

0%25%50%75%100%151015202531
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1441523
2442522
3543502
4544492
5545482
6546472
7547461
8548461
9649451
10649441
11650441
12650431
13651430
14651430
15651430
16651430
17651430
18651430
19651430
20651430
21652420
22652420
23751420
24751420
25752410
26851410
27852400
28951400
29953380
301053370
311054360

Wind in December

Winds average 7 mph in December.

Across December, daily wind ranges from about 7 mph on the calmest days to 7 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm
317calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 10 h 54 min at the start of December to 10 h 48 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 6 minutes over December. Sunrise moves from 6:43 AM to 6:59 AM, and sunset from 5:37 PM to 5:48 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
110.96:435:37
210.96:445:37
310.96:455:37
410.96:455:37
510.96:465:38
610.96:465:38
710.96:475:38
810.86:485:38
910.86:485:39
1010.86:495:39
1110.86:495:39
1210.86:505:40
1310.86:505:40
1410.86:515:40
1510.86:525:41
1610.86:525:41
1710.86:535:41
1810.86:535:42
1910.86:545:42
2010.86:545:43
2110.86:555:43
2210.86:555:44
2310.86:565:44
2410.86:565:45
2510.86:565:45
2610.86:575:46
2710.86:575:46
2810.86:585:47
2910.86:585:47
3010.86:585:48
3110.86:595:48

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 4.17 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 4.17 kWh/m² to a high of 6.68 kWh/m² in June across the year — December's 4.17 kWh/m² sits near the bottom.

012345151015202531
Solar energy (kWh/m²)Level
14.1Bright
24.1Bright
34.0Bright
44.0Bright
54.0Bright
64.0Bright
74.0Bright
84.0Bright
94.0Bright
104.0Bright
114.0Bright
124.0Bright
134.0Bright
144.0Bright
154.0Bright
164.1Bright
174.1Bright
184.1Bright
194.1Bright
204.1Bright
214.1Bright
224.2Bright
234.2Bright
244.2Bright
254.2Bright
264.3Bright
274.3Bright
284.3Bright
294.3Bright
304.4Bright
314.4Bright
Planning a trip in December

Hazard calendar for Hilo

In seasonPeak

None of Hilo's seasonal hazards are active in December. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Hilo sits in the eastern Pacific hurricane zone; the season peaks August–September.

Pacific hurricane
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is December a good time to visit Hilo?

Our two travel scores rate December for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

5.1
Sightseeing
3rd-best month of the year
4.0
Beach & pool
9th-best month of the year

December is a reasonable time to visit Hilo for sightseeing.

What to pack for Hilo in December

From December's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In December, Hilo sees daytime highs around 73°F and nights near 68°F. Pack rain gear. Worth having: light clothes. About 22 days see rain.

rain gearlight clothes

Sea temperature near Hilo in December

The nearest coast averages about 77°F in December — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 11 mi away) is warmest in September at about 80°F and coldest in March near 75°F.

The water stays above 68°F all year — warm enough for a swim any month.

74°76°78°80°82°JanFebMarAprMayJunJulAugSepOctNovDecrefreshingwarmcomfortable to swim
Sea temperature (°F)Comfort
Jan76Warm
Feb75Warm
Mar75Warm
Apr76Warm
May77Warm
Jun78Warm
Jul79Warm
Aug79Warm
Sep80Warm
Oct80Warm
Nov78Warm
Dec77Warm

UV index in Hilo in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Hilo peaks around August 15 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 16 at about 7 (high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecVery highExtremeVery highHighAug 15UV 14Dec 16UV 7
UV index (midday)Level
Jan8Very high
Feb10Very high
Mar12Extreme
Apr14Extreme
May11Extreme
Jun13Extreme
Jul13Extreme
Aug14Extreme
Sep13Extreme
Oct10Extreme
Nov8Very high
Dec7High

Air quality in Hilo in December

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where December falls, not just the annual average.

Air quality in Hilo is worst in January — around 28 µg/m³ PM2.5 (moderate), about 1.7× the cleanest month (July, 16 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateJan 2128 µg/m³Jul 1917 µg/m³
PM2.5 (µg/m³)Level
Jan28Moderate
Feb27Moderate
Mar26Moderate
Apr23Moderate
May22Moderate
Jun19Moderate
Jul16Moderate
Aug18Moderate
Sep21Moderate
Oct25Moderate
Nov22Moderate
Dec24Moderate
Location & terrain

Where is Hilo?

Hilo sits at 19.7°N, 155.1°W, 59 ft above sea level, in United States. The nearest listed city is Kīhei, 113 mi away.

Topography around Hilo

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Hilo.

Within 2 miles, the terrain around Hilo has only modest variations in elevation — a maximum elevation change of 774 ft around an average of 197 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 3,606 ft; within 50 miles, extreme variations in elevation — a maximum elevation change of 13,750 ft.

The land around Hilo is covered by trees (34%), water (29%) and grassland (22%) within 2 miles, trees (42%) and water (29%) within 10 miles, and water (49%) and grassland (20%) within 50 miles.

2 miles
774 ft
10 miles
3,606 ft
50 miles
13,750 ft
treesshrubsgrasslandartificial surfacesbare terrainwater
December weather nearby: Kīhei 113 mi · Kahului 120 mi · Wailuku 122 mi · Lahaina 130 mi · Hawai‘i Kai 201 mi · East Honolulu 201 mi · Niu Valley 202 mi · Kuliouou - Kalani Iki 203 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Hilo (19.7299°, -155.0907°, elevation 59 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).