Yilan weather in December

In December, Yilan sees average daytime highs of 18°C and overnight lows near 14°C, with 244 mm of rain across 21.7 wet days and about 10.5 hours of daylight. It is the 10th-warmest and 8th-wettest month of the year here.

Highs ease over the month, from about 19°C in the first days to 17°C by the end. The sky is clear or mostly clear about 9% of the time in December, and the air most often feels dry.

Daylight stretches from about 10 h 36 min at the start of December to 10 h 30 min by month's end. Set against the rest of the year, December is Yilan's 9th-clearest and 1st-windiest month. For the whole year in context, see Yilan's year-round climate.

Daytime high
18°
10th warmest
Overnight low
14°
3rd coldest
Rainfall
244 mm
21.7 wet days
Daylight
10 h 30 min
6:35 AM – 5:03 PM
Cloud cover
81%
9th clearest
Wind
9 km/h
1st windiest
Solar energy
2.07 kWh/m²
Travel score
4.1
out of 10

Yilan is A county-administered city in Yilan County, Taiwan.

Density
3,203/km²
people per km²
Founded
1945

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

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 19°C in the first days to 17°C by the end.

A typical December day in Yilan reaches about 18°C in the afternoon and slips back to 14°C overnight — a 4°C spread between the day's warmth and the night's chill. On most days the high lands between 14°C and 22°C. Set against its neighbours, December runs about 3°C cooler than November and about 2°C warmer than January.

10°15°20°25°151015202531
Avg high (°C)Avg low (°C)
12016
22016
31916
41916
51916
61915
71915
81915
91915
101915
111915
121815
131815
141815
151814
161814
171814
181814
191814
201814
211814
221814
231814
241714
251714
261714
271714
281713
291713
301713
311713

How December really feels in Yilan

Once humidity and wind are folded in, December averages 0 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

December sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Yilan weather by month

How December compares with the rest of the year at a glance. December is the 10th-warmest and 8th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan17° / 13°1902210.63.6
Feb17° / 13°16419.711.13.9
Mar19° / 15°15219.911.84.6
Apr22° / 18°18520.812.64.8
May25° / 21°29725.213.24.3
Jun28° / 24°31925.313.53.6
Jul30° / 25°27122.313.43.7
Aug29° / 25°32922.912.93.7
Sep27° / 24°33620.512.24.6
Oct24° / 21°39421.611.44.9
Nov21° / 18°3362110.84.6
Dec18° / 14°24421.710.54.1

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 9% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 9% of December, with mostly cloudy or overcast conditions the remaining 82%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
12080
22080
32080
41981
51882
61882
71882
81882
91882
101882
111882
121783
131783
141783
151783
161783
171783
181882
191882
201783
211783
221783
231783
241882
251882
261882
271882
281981
291981
301981
311783

Chance of precipitation in December

Any precipitation

Yilan gets around 244 mm of rain over 21.7 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 70% and peaks near 72% on the wettest days.

0%20%40%60%80%151015202531
Rain chance (%)
170
270
370
470
570
670
770
871
971
1072
1172
1272
1372
1472
1572
1672
1771
1871
1970
2070
2170
2269
2369
2468
2568
2667
2767
2867
2967
3067
3168

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, December lands in the dry band about 40% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
127253513
228263312
330273211
431283111
532293010
63330299
73331278
83431278
93532267
103632267
113632256
123733256
133732255
143832255
153932254
164032254
174032243
184132243
194331233
204431232
214531222
224631212
234731212
244831202
254931191
265031181
275032171
285032171
295132161
305133160
315133160

Wind in December

Winds average 9 km/h in December, the windiest month of the year.

Across December, daily wind ranges from about 9 km/h on the calmest days to 9 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
19calm
29calm
39calm
49calm
59calm
69calm
79calm
89calm
99calm
109calm
119calm
129calm
139calm
149calm
159calm
169calm
179calm
189calm
199calm
209calm
219calm
229calm
239calm
249calm
259calm
269calm
279calm
289calm
299calm
309calm
319calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 10 h 36 min at the start of December to 10 h 30 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 6:26 AM to 6:42 AM, and sunset from 5:00 PM to 5:11 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
110.66:265:00
210.66:265:00
310.66:275:00
410.56:285:00
510.56:285:00
610.56:295:01
710.56:305:01
810.56:305:01
910.56:315:01
1010.56:315:01
1110.56:325:02
1210.56:335:02
1310.56:335:02
1410.56:345:03
1510.56:345:03
1610.56:355:03
1710.56:365:04
1810.56:365:04
1910.56:375:04
2010.56:375:05
2110.56:385:05
2210.56:385:06
2310.56:395:06
2410.56:395:07
2510.56:395:07
2610.56:405:08
2710.56:405:08
2810.56:415:09
2910.56:415:09
3010.56:415:10
3110.56:425:11

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 2.07 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 2.07 kWh/m² to a high of 5.81 kWh/m² in July across the year — December's 2.07 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
12.2Moderate
22.2Moderate
32.2Moderate
42.2Moderate
52.2Moderate
62.1Moderate
72.1Moderate
82.1Moderate
92.1Moderate
102.1Moderate
112.1Moderate
122.1Moderate
132.1Moderate
142.0Moderate
152.0Moderate
162.0Moderate
172.0Moderate
182.0Moderate
192.1Moderate
202.1Moderate
212.1Moderate
222.1Moderate
232.1Moderate
242.1Moderate
252.1Moderate
262.1Moderate
272.1Moderate
282.1Moderate
292.1Moderate
302.2Moderate
312.2Moderate
Planning a trip in December

Hazard calendar for Yilan

In seasonPeak

In December, Yilan sits inside its pacific typhoon season. The full year is below, with each hazard's peak months called out.

Yilan sits in the Pacific typhoon belt; the season peaks July–October.

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

Is December a good time to visit Yilan?

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

4.1
Sightseeing
7th-best month of the year
1.5
Beach & pool
10th-best month of the year

December is a reasonable time to visit Yilan for sightseeing.

What to pack for Yilan in December

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

In December, Yilan sees daytime highs around 18°C and nights near 14°C. Pack rain gear. About 22 days see rain.

rain gear

Sea temperature near Yilan in December

The nearest coast averages about 23°C 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 18 km away) is warmest in August at about 28°C and coldest in January near 22°C.

The water stays above 20°C all year — warm enough for a swim any month.

20°22°24°26°28°30°JanFebMarAprMayJunJulAugSepOctNovDecrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan22Refreshing
Feb22Refreshing
Mar23Refreshing
Apr24Warm
May26Warm
Jun27Warm
Jul28Tropical
Aug28Tropical
Sep28Warm
Oct26Warm
Nov25Warm
Dec23Refreshing

UV index in Yilan in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 5 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Yilan peaks around July 14 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 at about 5 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecHighVery highExtremeVery highHighJul 14UV 11Dec 21UV 5
UV index (midday)Level
Jan6High
Feb8Very high
Mar9Very high
Apr7High
May10Extreme
Jun11Extreme
Jul12Extreme
Aug10Very high
Sep11Extreme
Oct8Very high
Nov7High
Dec5Moderate

Air quality in Yilan 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 Yilan is worst in April — around 52 µg/m³ PM2.5 (poor), about 2.1× the cleanest month (October, 25 µg/m³).

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

0204060JanFebMarAprMayJunJulAugSepOctNovDecPoorModerateApr 1052 µg/m³Oct 1626 µg/m³
PM2.5 (µg/m³)Level
Jan38Poor
Feb43Poor
Mar51Poor
Apr52Poor
May44Poor
Jun41Poor
Jul32Moderate
Aug32Moderate
Sep30Moderate
Oct25Moderate
Nov32Moderate
Dec32Moderate
Location & terrain

Where is Yilan?

Yilan sits at 24.8°N, 121.8°E, 15 m above sea level, in Taiwan. The nearest listed city is Xizhi, 36 km away.

XizhiNeihuTaipeiJiufenBanqiaoKeelungShulinSanxia

Topography around Yilan

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Yilan.

Within 3 km, the terrain around Yilan has only modest variations in elevation — a maximum elevation change of 33 m around an average of 9 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,413 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,839 m.

The land around Yilan is covered by cropland (40%), artificial surfaces (35%) and trees (21%) within 3 km, trees (50%) and water (23%) within 16 km, and trees (47%) and water (46%) within 80 km.

3 km
33 m
16 km
1,413 m
80 km
3,839 m
treesgrasslandcroplandartificial surfaceswater
December weather nearby: Xizhi 36 km · Neihu 40 km · Taipei 40 km · Jiufen 40 km · Banqiao 41 km · Keelung 42 km · Shulin 42 km · Sanxia 43 km

Taiwan travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type A / B
110 / 220 V · 60 Hz
Happiness
6.7 / 10
World Happiness, 2025
Religion
Buddhist 35%Taoist 33%none or unspecified 18%folk religion approximately 10%

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 Yilan (24.757°, 121.753°, elevation 15 m), 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).