Bolu in Winter
In winter (December, January and February), Bolu sees average daytime highs around 5°C and overnight lows near -3°C, with 275 mm of precipitation over about 41 wet days across the season. It is the coldest season of the year and the 2nd-wettest season.
Across winter, daytime highs hold fairly steady around 5°C. The sky is clear or mostly clear about 24% of the time across winter, and the air most often feels dry.
Winter is Bolu's weakest season of the year to visit on our travel score. For the whole year in context, see Bolu's year-round climate.
- Avg daytime high
- 5°C
- coldest season of the year
- Avg overnight low
- -3°C
- Precipitation
- 275 mm
- 41 wet days
- Avg wind
- 7 km/h
- Travel score
- 0.2
- weakest season of the year
- Months
- Dec · Jan · Feb
Temperature in Bolu in Winter
Across winter, daytime highs hold fairly steady around 5°C.
A typical winter day in Bolu reaches about 5°C and drops to -3°C overnight. The warmest of the three months is December, the coolest January.
How winter really feels in Bolu
Once humidity and wind are folded in, winter brings about 0 days that feel above 32°C and 90 that feel at or below 0°C.
The story in winter is cold — wind chill drags the overnight "feels like" below the raw low.
Bolu weather by month
How the three winter months (December, January and February) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 4° / -4° | 91 | 13.9 | 11 | 9.4 | 0.0 |
| Feb | 5° / -3° | 88 | 13.8 | 10 | 10.4 | 0.2 |
| Mar | 9° / -0° | 107 | 14.9 | 8.5 | 11.7 | 1.6 |
| Apr | 14° / 4° | 99 | 14.4 | 2.5 | 13.1 | 3.5 |
| May | 18° / 8° | 110 | 15.9 | 0.1 | 14.2 | 5.2 |
| Jun | 22° / 11° | 96 | 13.3 | 0 | 14.9 | 6.3 |
| Jul | 24° / 14° | 50 | 8.6 | 0 | 14.6 | 7.6 |
| Aug | 25° / 14° | 52 | 8.3 | 0 | 13.6 | 7.7 |
| Sep | 22° / 11° | 66 | 8.8 | 0 | 12.3 | 7.1 |
| Oct | 17° / 7° | 90 | 11.2 | 0.8 | 10.9 | 5.4 |
| Nov | 11° / 2° | 75 | 10.3 | 3.6 | 9.7 | 2.8 |
| Dec | 6° / -2° | 96 | 13.4 | 8.2 | 9.1 | 0.4 |
Cloud cover in Winter
The sky is clear or mostly clear about 24% of the time across winter.
Chance of precipitation in Winter
Bolu gets around 275 mm of rain and snow over 41 wet days across winter. The line is the day-by-day chance of measurable precipitation.
Humidity in Winter
Most of winter feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Winter
Winds average 7 km/h across winter.
Sunrise & sunset in Winter
Daylight runs from about 9 h 18 min in early December to 10 h 54 min by late February. The lit band spans sunrise to sunset each day.
Solar energy in Winter
Average shortwave solar energy reaching the ground each day across winter, about 2.2 kWh/m².
Is winter a good time to visit Bolu?
Our two travel scores rate winter for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
winter is a weaker month for outdoor sightseeing in Bolu.
What to pack for Bolu in Winter
From winter's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In winter, Bolu sees daytime highs around 5°C and nights near -3°C. Pack a warm layer, a heavy coat and rain gear. About 41 days see rain.
Sea temperature near Bolu in Winter
The nearest coast averages about 9°C across winter — 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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 9 | 7 | 8 | 11 | 16 | 21 | 24 | 25 | 23 | 20 | 15 | 12 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Cool | Refreshing | Refreshing | Warm | Refreshing | Cool | Cool | Bracing |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 9 | Bracing |
| Feb | 7 | Bracing |
| Mar | 8 | Bracing |
| Apr | 11 | Bracing |
| May | 16 | Cool |
| Jun | 21 | Refreshing |
| Jul | 24 | Refreshing |
| Aug | 25 | Warm |
| Sep | 23 | Refreshing |
| Oct | 20 | Cool |
| Nov | 15 | Cool |
| Dec | 12 | Bracing |
UV index in Bolu in Winter
Clear-sky midday UV across winter averages 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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 2 | 2 | 3 | 7 | 7 | 9 | 9 | 9 | 6 | 4 | 2 | 2 |
| Level | Low | Moderate | Moderate | High | Very high | Very high | Very high | Very high | High | Moderate | Moderate | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 2 | Low |
| Feb | 2 | Moderate |
| Mar | 3 | Moderate |
| Apr | 7 | High |
| May | 7 | Very high |
| Jun | 9 | Very high |
| Jul | 9 | Very high |
| Aug | 9 | Very high |
| Sep | 6 | High |
| Oct | 4 | Moderate |
| Nov | 2 | Moderate |
| Dec | 2 | Low |
Air quality in Bolu in Winter
Average fine-particle pollution (PM2.5) through the year — so you can see where winter 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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 20 | 23 | 32 | 33 | 33 | 26 | 21 | 21 | 20 | 22 | 22 | 19 |
| Level | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 20 | Moderate |
| Feb | 23 | Moderate |
| Mar | 32 | Moderate |
| Apr | 33 | Moderate |
| May | 33 | Moderate |
| Jun | 26 | Moderate |
| Jul | 21 | Moderate |
| Aug | 21 | Moderate |
| Sep | 20 | Moderate |
| Oct | 22 | Moderate |
| Nov | 22 | Moderate |
| Dec | 19 | Moderate |
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.
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
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.