Bolu weather in April

In April, Bolu sees average daytime highs of 14°C and overnight lows near 4°C, with 99 mm of precipitation across 14.4 wet days and about 13.1 hours of daylight. It is the 7th-warmest and 3rd-wettest month of the year here.

Highs climb over the month, from about 12°C in the first days to 15°C by the end. The sky is clear or mostly clear about 25% of the time in April, and the air most often feels dry.

Daylight stretches from about 12 h 24 min at the start of April to 13 h 42 min by month's end. Set against the rest of the year, April is Bolu's 8th-clearest and 6th-windiest month. For the whole year in context, see Bolu's year-round climate.

Daytime high
14°
7th warmest
Overnight low
6th coldest
Precipitation
99 mm
14.4 wet days
Daylight
13 h 06 min
5:21 AM – 6:26 PM
Cloud cover
62%
8th clearest
Wind
6 km/h
6th windiest
Solar energy
5.23 kWh/m²
Travel score
3.5
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 April

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 12°C in the first days to 15°C by the end.

A typical April day in Bolu reaches about 14°C in the afternoon and slips back to 4°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 7°C and 20°C. Set against its neighbours, April runs about 5°C warmer than March and about 4°C cooler than May.

10°20°151015202530
Avg high (°C)Avg low (°C)
1122
2122
3122
4122
5122
6122
7133
8133
9133
10133
11133
12133
13133
14143
15144
16144
17144
18144
19144
20144
21144
22144
23154
24155
25155
26155
27155
28155
29165
30166

How April really feels in Bolu

Once humidity and wind are folded in, April averages 0 days that feel above 32°C and 2 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
2
wind chill below the day's low

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

Bolu weather by month

How April compares with the rest of the year at a glance. April is the 7th-warmest and 3rd-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 April

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 25% of the time in April.

Beyond those clear spells, partly cloudy skies cover about 16% of April, with mostly cloudy or overcast conditions the remaining 59%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14060
24060
33961
44060
54060
64060
74060
84159
94159
104159
114159
124060
134060
144060
154060
164060
174060
184159
194060
204159
214258
224258
234258
244357
254456
264456
274456
284654
294654
304654

Chance of precipitation in April

Any precipitationSnow

Bolu gets around 99 mm of rain and snow over 14.4 wet days in April. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 48% and peaks near 50% on the wettest days, and about 3 days bring snow.

0%20%40%60%151015202530
Rain chance (%)Snow chance (%)
14915
25014
35014
45013
55013
65012
75011
85011
95010
104910
114910
124910
134910
14499
15499
16489
17488
18478
19477
20477
21467
22466
23466
24465
25455
26454
27454
28453
29453
30452

Humidity in April

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, April 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%151015202530
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

Wind in April

Winds average 6 km/h in April.

Across April, daily wind ranges from about 5 km/h on the calmest days to 6 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
295calm
305calm

Sunrise & sunset in April

DaylightNight

Daylight runs from about 12 h 24 min at the start of April to 13 h 42 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 78 minutes over April. Sunrise moves from 5:46 AM to 5:01 AM, and sunset from 6:10 PM to 6:41 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.45:466:10
212.55:446:11
312.55:436:12
412.55:416:14
512.65:396:15
612.65:386:16
712.75:366:17
812.75:346:18
912.85:336:19
1012.85:316:20
1112.95:296:21
1212.95:286:22
1313.05:266:23
1413.05:246:24
1513.05:236:25
1613.15:216:26
1713.15:206:27
1813.25:186:28
1913.25:176:29
2013.35:156:31
2113.35:146:32
2213.35:126:33
2313.45:116:34
2413.45:096:35
2513.55:086:36
2613.55:066:37
2713.65:056:38
2813.65:036:39
2913.65:026:40
3013.75:016:41

Solar energy in April

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in April, about 5.23 kWh/m².

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 — April's 5.23 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
14.7Bright
24.7Bright
34.8Bright
44.8Bright
54.9Bright
64.9Bright
74.9Bright
85.0Bright
95.0Bright
105.0Bright
115.1Bright
125.1Bright
135.1Bright
145.2Bright
155.2Bright
165.2Bright
175.3Bright
185.3Bright
195.3Bright
205.3Bright
215.4Bright
225.4Bright
235.5Bright
245.5Bright
255.5Bright
265.6Bright
275.6Bright
285.6Bright
295.7Bright
305.7Bright
Planning a trip in April

Is April a good time to visit Bolu?

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

3.5
Sightseeing
7th-best month of the year
0.1
Beach & pool
7th-best month of the year

April is a weaker month for outdoor sightseeing in Bolu.

What to pack for Bolu in April

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

In April, Bolu sees daytime highs around 14°C and nights near 4°C. Pack rain gear. Worth having: a warm layer and sun protection. About 14 days see rain.

rain geara warm layersun protection

Sea temperature near Bolu in April

The nearest coast averages about 11°C in April — 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 April

LowModerateHighVery highExtreme

Clear-sky midday UV in April 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 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 April

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where April 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
April 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).