Mostar weather in September

In September, Mostar sees average daytime highs of 24°C and overnight lows near 13°C, with 135 mm of rain across 9.1 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 6th-wettest month of the year here.

Highs ease over the month, from about 27°C in the first days to 22°C by the end. The sky is clear or mostly clear about 50% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 hours at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Mostar's 4th-clearest and 8th-windiest month. For the whole year in context, see Mostar's year-round climate.

Daytime high
24°
4th warmest
Overnight low
13°
9th coldest
Rainfall
135 mm
9.1 wet days
Daylight
12 h 18 min
5:34 AM – 5:52 PM
Cloud cover
44%
4th clearest
Wind
6 km/h
8th windiest
Solar energy
4.46 kWh/m²
Travel score
7.1
out of 10

Mostar is town in Bosnia and Herzegovina.

Density
89/km²
people per km²
Founded
1452

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 27°C in the first days to 22°C by the end.

A typical September day in Mostar reaches about 24°C in the afternoon and slips back to 13°C overnight — a 12°C spread between the day's warmth and the night's chill. On most days the high lands between 19°C and 29°C. Set against its neighbours, September runs about 6°C cooler than August and about 5°C warmer than October.

10°20°30°151015202530
Avg high (°C)Avg low (°C)
12715
22715
32714
42614
52614
62614
72614
82614
92514
102513
112513
122513
132513
142413
152413
162413
172412
182412
192312
202312
212312
222312
232312
242211
252211
262211
272211
282211
292211
302111

How September really feels in Mostar

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.

Mostar weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 6th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -1°13911.14.39.21.0
Feb / -0°13410.9510.21.6
Mar13° / 13311.83.311.63.4
Apr17° / 14713.11.313.24.9
May22° / 10°10912.4014.56.3
Jun26° / 14°729.8015.26.9
Jul29° / 17°456.8014.96.2
Aug30° / 17°536.6013.86.0
Sep24° / 13°1359.1012.37.1
Oct19° / 18010.80.410.86.0
Nov13° / 22213.21.89.53.4
Dec / 19112.53.68.81.4

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 50% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 16% of September, with mostly cloudy or overcast conditions the remaining 34%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
17624
27525
37426
47426
57228
67129
77129
87030
96931
106931
116832
126733
136634
146634
156535
166535
176436
186436
196337
206337
216337
226238
236238
246040
256040
266040
275941
285941
295941
305842

Chance of precipitation in September

Any precipitation

Mostar gets around 135 mm of rain over 9.1 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 31% and peaks near 34% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
127
228
328
429
529
629
730
830
930
1030
1131
1231
1331
1431
1531
1631
1731
1831
1931
2031
2131
2231
2332
2432
2532
2632
2733
2833
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 61% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
1454312
2474212
3484111
4494011
5503911
6523810
7533710
8543610
956359
1056359
1157349
1259338
1360328
1461318
1562308
1664297
1765287
1865287
1966277
2067267
2168257
2269256
2369256
2470246
2570246
2670246
2770246
2871245
2971245
3071245

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 hours 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 84 minutes over September. Sunrise moves from 5:17 AM to 5:51 AM, and sunset from 6:20 PM to 5:26 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.05:176:20
213.05:186:18
312.95:206:16
412.95:216:14
512.85:226:12
612.85:236:11
712.75:246:09
812.75:256:07
912.65:266:05
1012.65:276:03
1112.55:296:01
1212.55:305:59
1312.45:315:58
1412.45:325:56
1512.35:335:54
1612.35:345:52
1712.25:355:50
1812.25:375:48
1912.15:385:46
2012.15:395:44
2112.05:405:42
2212.05:415:40
2311.95:425:39
2411.95:445:37
2511.85:455:35
2611.85:465:33
2711.75:475:31
2811.75:485:29
2911.65:495:27
3011.65:515:26

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.46 kWh/m².

For context, solar energy here swings from a low near 1.46 kWh/m² to a high of 6.79 kWh/m² in July across the year — September's 4.46 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.3Bright
25.2Bright
35.1Bright
45.1Bright
55.0Bright
65.0Bright
74.9Bright
84.8Bright
94.8Bright
104.7Bright
114.7Bright
124.6Bright
134.6Bright
144.5Bright
154.5Bright
164.4Bright
174.4Bright
184.3Bright
194.3Bright
204.2Bright
214.2Bright
224.1Bright
234.1Bright
244.0Bright
254.0Moderate
263.9Moderate
273.9Moderate
283.8Moderate
293.8Moderate
303.7Moderate
Planning a trip in September

Is September a good time to visit Mostar?

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

7.1
Sightseeing
1st-best month of the year
5.9
Beach & pool
4th-best month of the year

September is one of the better times to visit Mostar for general sightseeing.

What to pack for Mostar in September

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

In September, Mostar sees daytime highs around 24°C and nights near 13°C. Worth packing: light clothes and rain gear. About 9 days see rain.

light clothesrain gear

Sea temperature near Mostar in September

The nearest coast averages about 23°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 60 km away) is warmest in August at about 25°C and coldest in February near 13°C.

It's comfortable for a long swim from Jun 1 to Oct 29 — about 5 months when the water holds above 20°C.

10°15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan14Bracing
Feb13Bracing
Mar13Bracing
Apr15Bracing
May18Cool
Jun22Refreshing
Jul24Warm
Aug25Warm
Sep23Refreshing
Oct21Refreshing
Nov19Cool
Dec16Cool

UV index in Mostar in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 6 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Mostar peaks around July 17 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 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 highModerateLowJul 17UV 9Dec 21UV 1
UV index (midday)Level
Jan1Low
Feb3Moderate
Mar5High
Apr7Very high
May7Very high
Jun9Very high
Jul9Very high
Aug9Very high
Sep6High
Oct4Moderate
Nov2Low
Dec1Low

Air quality in Mostar 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 Mostar is worst in August — around 16 µg/m³ PM2.5 (moderate), about 2.5× the cleanest month (December, 6 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodModerateGoodAug 1515 µg/m³Dec 186 µg/m³
PM2.5 (µg/m³)Level
Jan7Good
Feb10Good
Mar12Good
Apr16Moderate
May13Moderate
Jun12Moderate
Jul11Good
Aug16Moderate
Sep8Good
Oct7Good
Nov7Good
Dec6Good
Location & terrain

Where is Mostar?

Mostar sits at 43.3°N, 17.8°E, 66 m above sea level, in Bosnia and Herzegovina. The nearest listed city is Međugorje, 20 km away.

MeđugorjeKonjicNeumIlidžaKorčulaSarajevoVisokoDubrovnik

Topography around Mostar

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

Within 3 km, the terrain around Mostar has large variations in elevation — a maximum elevation change of 661 m around an average of 217 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,873 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,364 m.

The land around Mostar is covered by trees (35%), shrubs (26%) and artificial surfaces (23%) within 3 km, trees (50%) and grassland (28%) within 16 km, and trees (52%) and grassland (24%) within 80 km.

3 km
661 m
16 km
1,873 m
80 km
2,364 m
treesshrubsgrasslandcroplandartificial surfaceswater
September weather nearby: Međugorje 20 km · Konjic 36 km · Neum 49 km · Ilidža 68 km · Korčula 69 km · Sarajevo 71 km · Visoko 78 km · Dubrovnik 82 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 Mostar (43.3433°, 17.8081°, elevation 66 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).