Bolu weather in December

In December, Bolu sees average daytime highs of 6°C and overnight lows near -2°C, with 96 mm of precipitation across 13.4 wet days and about 9.1 hours of daylight. It is the 10th-warmest and 5th-wettest month of the year here.

Highs ease over the month, from about 8°C in the first days to 4°C by the end. The sky is clear or mostly clear about 24% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 18 min at the start of December to 9 h 06 min by month's end. Set against the rest of the year, December is Bolu's 9th-clearest and 2nd-windiest month. For the whole year in context, see Bolu's year-round climate.

Daytime high
10th warmest
Overnight low
-2°
3rd coldest
Precipitation
96 mm
13.4 wet days
Daylight
9 h 06 min
7:17 AM – 4:23 PM
Cloud cover
66%
9th clearest
Wind
7 km/h
2nd windiest
Solar energy
1.72 kWh/m²
Travel score
0.4
out of 10

Bolu is central district and city in Bolu Province, Turkey.

Air quality
Elevated
PM2.5 24.4 µg/m³ · 2019
Density
6,840/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

Highs ease over the month, from about 8°C in the first days to 4°C by the end.

A typical December day in Bolu reaches about 6°C in the afternoon and slips back to -2°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between -1°C and 11°C. Set against its neighbours, December runs about 5°C cooler than November and about 2°C warmer than January.

-10°-5°10°15°151015202531
Avg high (°C)Avg low (°C)
180
280
380
480
570
670
77-1
87-1
97-1
106-1
116-1
126-1
136-1
146-1
156-2
165-2
175-2
185-2
195-2
205-2
215-2
225-2
235-2
245-2
255-2
265-2
275-2
285-2
294-2
304-2
314-3

How December really feels in Bolu

Once humidity and wind are folded in, December averages 0 days that feel above 32°C and 31 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
31
wind chill below the day's low

The story in December is cold — wind chill drags the overnight "feels like" below the raw low.

Bolu weather by month

How December compares with the rest of the year at a glance. December is the 10th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -4°9113.9119.40.0
Feb / -3°8813.81010.40.2
Mar / -0°10714.98.511.71.6
Apr14° / 9914.42.513.13.5
May18° / 11015.90.114.25.2
Jun22° / 11°9613.3014.96.3
Jul24° / 14°508.6014.67.6
Aug25° / 14°528.3013.67.7
Sep22° / 11°668.8012.37.1
Oct17° / 9011.20.810.95.4
Nov11° / 7510.33.69.72.8
Dec / -2°9613.48.29.10.4

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 24% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 12% of December, with mostly cloudy or overcast conditions the remaining 64%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14258
24258
34060
44060
53961
63862
73862
83763
93763
103763
113664
123664
133763
143664
153664
163664
173664
183664
193664
203565
213565
223565
233565
243565
253565
263565
273367
283367
293367
303367
313268

Chance of precipitation in December

Any precipitationSnow

Bolu gets around 96 mm of rain and snow over 13.4 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 44% and peaks near 47% on the wettest days, and about 8 days bring snow.

0%20%40%60%151015202531
Rain chance (%)Snow chance (%)
14219
24220
34320
44321
54321
64422
74423
84423
94424
104424
114425
124425
134426
144426
154427
164427
174428
184428
194428
204429
214329
224429
234430
244430
254431
264532
274532
284633
294634
304634
314735

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 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)
1100
2100
3100
4100
5100
6100
7100
8100
9100
10100
11100
12100
13100
14100
15100
16100
17100
18100
19100
20100
21100
22100
23100
24100
25100
26100
27100
28100
29100
30100
31100

Wind in December

Winds average 7 km/h in December.

Across December, daily wind ranges from about 6 km/h on the calmest days to 7 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
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 9 h 18 min at the start of December to 9 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 12 minutes over December. Sunrise moves from 7:04 AM to 7:23 AM, and sunset from 4:22 PM to 4:30 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.37:044:22
29.37:054:22
39.37:064:22
49.27:074:22
59.27:084:22
69.27:094:21
79.27:104:21
89.27:114:21
99.27:124:21
109.17:134:22
119.17:134:22
129.17:144:22
139.17:154:22
149.17:164:22
159.17:164:22
169.17:174:23
179.17:184:23
189.17:184:23
199.17:194:24
209.17:194:24
219.17:204:24
229.17:204:25
239.17:214:25
249.17:214:26
259.17:224:26
269.17:224:27
279.17:224:28
289.17:234:28
299.17:234:29
309.17:234:30
319.17:234:30

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 1.72 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 1.72 kWh/m² to a high of 6.88 kWh/m² in July across the year — December's 1.72 kWh/m² sits near the bottom.

00.511.522.5151015202531
Solar energy (kWh/m²)Level
11.9Dim
21.9Dim
31.8Dim
41.8Dim
51.8Dim
61.8Dim
71.8Dim
81.8Dim
91.8Dim
101.7Dim
111.7Dim
121.7Dim
131.7Dim
141.7Dim
151.7Dim
161.7Dim
171.7Dim
181.7Dim
191.7Dim
201.7Dim
211.7Dim
221.7Dim
231.7Dim
241.7Dim
251.7Dim
261.7Dim
271.7Dim
281.7Dim
291.7Dim
301.7Dim
311.7Dim
Planning a trip in December

Is December a good time to visit Bolu?

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

0.4
Sightseeing
10th-best month of the year
0.0
Beach & pool
9th-best month of the year

December is a weaker month for outdoor sightseeing in Bolu.

What to pack for Bolu in December

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

In December, Bolu sees daytime highs around 6°C and nights near -2°C. Pack a warm layer. Worth having: a heavy coat and rain gear. About 13 days see rain.

a warm layera heavy coatrain gear

Sea temperature near Bolu in December

The nearest coast averages about 12°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 47 km away) is warmest in August at about 25°C and coldest in February near 7°C.

It's comfortable for a long swim from Jun 11 to Oct 12 — about 4.1 months when the water holds above 20°C.

10°20°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan9Bracing
Feb7Bracing
Mar8Bracing
Apr11Bracing
May16Cool
Jun21Refreshing
Jul24Refreshing
Aug25Warm
Sep23Refreshing
Oct20Cool
Nov15Cool
Dec12Bracing

UV index in Bolu in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 2. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Bolu peaks around August 10 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateLowAug 10UV 9Dec 19UV 2
UV index (midday)Level
Jan2Low
Feb2Moderate
Mar3Moderate
Apr7High
May7Very high
Jun9Very high
Jul9Very high
Aug9Very high
Sep6High
Oct4Moderate
Nov2Moderate
Dec2Low

Air quality in Bolu 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 Bolu is worst in May — around 33 µg/m³ PM2.5 (moderate), about 1.7× the cleanest month (December, 19 µg/m³).

Seasonal pattern from CAMS reanalysis, scaled to Bolu's WHO annual average of 24.4 µg/m³.

010203040JanFebMarAprMayJunJulAugSepOctNovDecModerateMay 933 µg/m³Dec 2319 µg/m³
PM2.5 (µg/m³)Level
Jan20Moderate
Feb23Moderate
Mar32Moderate
Apr33Moderate
May33Moderate
Jun26Moderate
Jul21Moderate
Aug21Moderate
Sep20Moderate
Oct22Moderate
Nov22Moderate
Dec19Moderate
Location & terrain

Where is Bolu?

Bolu sits at 40.7°N, 31.6°E, 733 m above sea level, in Turkey. The nearest listed city is Kaynaşlı, 24 km away.

Topography around Bolu

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

Within 3 km, the terrain around Bolu has only modest variations in elevation — a maximum elevation change of 178 m around an average of 745 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,296 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,359 m.

The land around Bolu is covered by artificial surfaces (51%) and cropland (33%) within 3 km, trees (67%) within 16 km, and trees (63%) and grassland (21%) within 80 km.

3 km
178 m
16 km
1,296 m
80 km
2,359 m
treesgrasslandcroplandartificial surfacesbare terrainwater
December weather nearby: Kaynaşlı 24 km · Düzce 39 km · Gerede 50 km · Alaplı 53 km · Akçakoca 56 km · Devrek 61 km · Ereğli 63 km · Nallıhan 65 km

Turkey travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / F
230 V · 50 Hz
Prices
≈ 41% of US
price level, 2025
GDP per capita
$18,599
2025
Happiness
5.3 / 10
World Happiness, 2025
Homicide rate
3.2
per 100k, 2023
Road deaths
6.7
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Low
EF EPI 488
Religion
Muslim 100%other 0%

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 Bolu (40.7358°, 31.6061°, elevation 733 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. 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).