Banja Luka weather in September

In September, Banja Luka sees average daytime highs of 22°C and overnight lows near 11°C, with 95 mm of rain across 11 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 3rd-wettest month of the year here.

Highs ease over the month, from about 24°C in the first days to 20°C by the end. The sky is clear or mostly clear about 37% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 06 min at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Banja Luka's 4th-clearest and 9th-windiest month. For the whole year in context, see Banja Luka's year-round climate.

Daytime high
22°
4th warmest
Overnight low
11°
9th coldest
Rainfall
95 mm
11 wet days
Daylight
12 h 18 min
5:36 AM – 5:55 PM
Cloud cover
54%
4th clearest
Wind
6 km/h
9th windiest
Solar energy
3.74 kWh/m²
Travel score
6.6
out of 10

Banja Luka is city in Bosnia and Herzegovina.

Density
178/km²
people per km²
Founded
1494

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

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 24°C in the first days to 20°C by the end.

A typical September day in Banja Luka reaches about 22°C in the afternoon and slips back to 11°C overnight — a 11°C spread between the day's warmth and the night's chill. On most days the high lands between 16°C and 28°C. Set against its neighbours, September runs about 5°C cooler than August and about 5°C warmer than October.

10°20°30°151015202530
Avg high (°C)Avg low (°C)
12513
22413
32413
42413
52413
62412
72412
82312
92312
102312
112312
122312
132312
142211
152211
162211
172211
182211
192211
202111
212110
222110
232110
242110
252110
262110
272010
282010
29209
30209

How September really feels in Banja Luka

Once humidity and wind are folded in, September 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

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

Banja Luka weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -3°7010.4790.0
Feb / -2°7010.36.510.10.8
Mar12° / 7911.54.311.63.1
Apr17° / 9212.71.413.24.9
May21° / 10°11213.5014.66.0
Jun25° / 14°9711.9015.36.6
Jul27° / 15°8710.50156.7
Aug27° / 15°728.8013.97.0
Sep22° / 11°9511012.36.6
Oct17° / 729.20.610.75.6
Nov11° / 8510.239.42.7
Dec / -1°8211.56.18.70.2

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 37% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 18% of September, with mostly cloudy or overcast conditions the remaining 45%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
16238
26139
36040
46040
55941
65842
75842
85743
95743
105644
115644
125644
135545
145545
155545
165545
175545
185446
195446
205446
215248
225248
235248
245248
255248
265248
275248
285248
295149
305149

Chance of precipitation in September

Any precipitation

Banja Luka gets around 95 mm of rain over 11 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 36% and peaks near 38% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
133
233
334
434
535
636
736
837
937
1037
1138
1238
1338
1438
1538
1638
1738
1837
1937
2037
2137
2236
2336
2436
2535
2635
2735
2834
2934
3034

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the dry band about 57% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)
13735262
23935252
34035231
44235221
54335211
64436201
74536180
84637170
94737160
104837150
114937140
125037130
135137120
145336110
155436100
16563590
17583480
18603370
19613270
20643060
21662950
22682750
23702640
24712540
25722440
26742330
27752230
28762130
29782020
30782020

Wind in September

Winds average 6 km/h in September.

Across September, daily wind ranges from about 6 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
296calm
306calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 06 min at the start of September to 11 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 90 minutes over September. Sunrise moves from 5:18 AM to 5:54 AM, and sunset from 6:24 PM to 5:27 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.15:186:24
213.05:196:22
313.05:206:20
412.95:226:18
512.95:236:16
612.85:246:14
712.85:256:12
812.75:276:10
912.75:286:08
1012.65:296:06
1112.65:306:05
1212.55:316:03
1312.55:336:01
1412.45:345:59
1512.45:355:57
1612.35:365:55
1712.35:385:53
1812.25:395:51
1912.15:405:49
2012.15:415:47
2112.05:425:45
2212.05:445:43
2311.95:455:41
2411.95:465:39
2511.85:475:37
2611.85:495:35
2711.75:505:33
2811.75:515:31
2911.65:525:29
3011.65:545:27

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.74 kWh/m².

For context, solar energy here swings from a low near 1.22 kWh/m² to a high of 5.91 kWh/m² in July across the year — September's 3.74 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.5Bright
24.4Bright
34.3Bright
44.3Bright
54.2Bright
64.2Bright
74.1Bright
84.1Bright
94.0Bright
104.0Moderate
114.0Moderate
123.9Moderate
133.9Moderate
143.8Moderate
153.8Moderate
163.7Moderate
173.7Moderate
183.6Moderate
193.6Moderate
203.6Moderate
213.5Moderate
223.5Moderate
233.4Moderate
243.4Moderate
253.4Moderate
263.3Moderate
273.3Moderate
283.3Moderate
293.2Moderate
303.2Moderate
Planning a trip in September

Is September a good time to visit Banja Luka?

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

6.6
Sightseeing
3rd-best month of the year
4.7
Beach & pool
4th-best month of the year

September is a reasonable time to visit Banja Luka for sightseeing.

What to pack for Banja Luka in September

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

In September, Banja Luka sees daytime highs around 22°C and nights near 11°C. Worth packing: light clothes and rain gear. About 11 days see rain.

light clothesrain gear

UV index in Banja Luka in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September 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 Banja Luka peaks around July 11 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 20 at about 1 (low).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJul 11UV 8Dec 20UV 1
UV index (midday)Level
Jan1Low
Feb2Moderate
Mar5Moderate
Apr7High
May6High
Jun8Very high
Jul8Very high
Aug8Very high
Sep5High
Oct3Moderate
Nov2Low
Dec1Low

Air quality in Banja Luka in September

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Banja Luka is worst in April — around 15 µg/m³ PM2.5 (moderate), about 1.7× the cleanest month (December, 9 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1415 µg/m³Dec 149 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb11Good
Mar14Moderate
Apr15Moderate
May14Moderate
Jun14Moderate
Jul12Good
Aug13Moderate
Sep10Good
Oct10Good
Nov10Good
Dec9Good
Location & terrain

Where is Banja Luka?

Banja Luka sits at 44.8°N, 17.2°E, 151 m above sea level, in Bosnia and Herzegovina. The nearest listed city is Prijedor, 45 km away.

PrijedorJajceTeslicDobojTravnikPožegaSlavonski BrodBugojno

Topography around Banja Luka

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

Within 3 km, the terrain around Banja Luka has significant variations in elevation — a maximum elevation change of 286 m around an average of 181 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 831 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,855 m.

The land around Banja Luka is covered by artificial surfaces (46%) and trees (33%) within 3 km, trees (65%) and grassland (26%) within 16 km, and trees (72%) within 80 km.

3 km
286 m
16 km
831 m
80 km
1,855 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Prijedor 45 km · Jajce 49 km · Teslic 55 km · Doboj 70 km · Travnik 71 km · Požega 73 km · Slavonski Brod 77 km · Bugojno 83 km

Bosnia and Herzegovina travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / F
230 V · 50 Hz
Prices
≈ 40% of US
price level, 2025
GDP per capita
$10,382
2025
Happiness
6.4 / 10
World Happiness, 2025
Safe drinking water
86%
of population, 2024
Homicide rate
1.2
per 100k, 2023
Road deaths
13.5
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
High
EF EPI 591
Religion
Muslim 51%Orthodox 31%Roman Catholic 15%other 1%

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 Banja Luka (44.7788°, 17.2063°, elevation 151 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. 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).