Cluj-Napoca weather in September

In September, Cluj-Napoca sees average daytime highs of 20°C and overnight lows near 9°C, with 71 mm of rain across 10.3 wet days and about 12.4 hours of daylight. It is the 4th-warmest and 5th-wettest month of the year here.

Highs ease over the month, from about 22°C in the first days to 18°C by the end. The sky is clear or mostly clear about 36% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 12 min at the start of September to 11 h 30 min by month's end. Set against the rest of the year, September is Cluj-Napoca's 3rd-clearest and 5th-windiest month. For the whole year in context, see Cluj-Napoca's year-round climate.

Daytime high
20°
4th warmest
Overnight low
9th coldest
Rainfall
71 mm
10.3 wet days
Daylight
12 h 18 min
6:10 AM – 6:30 PM
Cloud cover
54%
3rd clearest
Wind
7 km/h
5th windiest
Solar energy
3.74 kWh/m²
Travel score
6.2
out of 10

Cluj-Napoca is city and seat of Cluj County in northwestern Romania.

Air quality
Elevated
PM2.5 17.8 µg/m³ · 2017
Density
1,597/km²
people per km²
Founded
1213

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 22°C in the first days to 18°C by the end.

A typical September day in Cluj-Napoca reaches about 20°C in the afternoon and slips back to 9°C overnight — a 11°C spread between the day's warmth and the night's chill. On most days the high lands between 14°C and 25°C. Set against its neighbours, September runs about 5°C cooler than August and about 6°C warmer than October.

10°20°30°151015202530
Avg high (°C)Avg low (°C)
12211
22211
32211
42210
52210
62110
72110
82110
92110
102110
11219
12209
13209
14209
15209
16209
17209
18199
19198
20198
21198
22198
23188
24188
25188
26188
27187
28187
29177
30177

How September really feels in Cluj-Napoca

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.

Cluj-Napoca weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -6°3486.58.80.0
Feb / -5°359.25.8100.0
Mar / -1°49103.811.61.5
Apr14° / 6812.61.313.33.9
May19° / 8915.9014.85.3
Jun22° / 12°10716015.65.8
Jul24° / 13°10215.6015.36.2
Aug25° / 13°8412.40146.8
Sep20° / 7110.3012.46.2
Oct14° / 5690.610.64.3
Nov / 428.639.21.2
Dec / -4°438.85.68.40.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 36% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 17% of September, with mostly cloudy or overcast conditions the remaining 47%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
16040
25941
35941
45743
55743
65743
75743
85545
95545
105644
115545
125545
135446
145347
155347
165347
175347
185248
195149
205149
215050
225050
235050
244951
254951
264951
274951
284951
294951
304951

Chance of precipitation in September

Any precipitation

Cluj-Napoca gets around 71 mm of rain over 10.3 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 34% and peaks near 37% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
137
237
336
436
535
635
735
834
934
1034
1134
1234
1334
1434
1534
1634
1734
1834
1935
2035
2135
2235
2334
2434
2534
2633
2732
2832
2931
3030

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 84% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
166295
268275
371254
474233
575223
677203
779192
880182
982171
1083161
1183161
1284151
1385150
1486140
1586140
1687130
1787130
1888120
1988120
2089110
2189110
2290100
2390100
249190
259190
269280
279280
289370
299370
309370

Wind in September

Winds average 7 km/h in September.

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

0246810151015202530
Wind speed (km/h)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 12 min at the start of September to 11 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 102 minutes over September. Sunrise moves from 5:50 AM to 6:29 AM, and sunset from 7:01 PM to 6:01 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.25:507:01
213.15:516:59
313.15:536:57
413.05:546:55
513.05:556:53
612.95:576:50
712.85:586:48
812.85:596:46
912.76:016:44
1012.76:026:42
1112.66:036:40
1212.66:056:38
1312.56:066:36
1412.46:076:34
1512.46:096:32
1612.36:106:30
1712.36:116:28
1812.26:136:26
1912.26:146:24
2012.16:156:21
2112.06:176:19
2212.06:186:17
2311.96:196:15
2411.96:216:13
2511.86:226:11
2611.86:246:09
2711.76:256:07
2811.66:266:05
2911.66:286:03
3011.56:296:01

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 1.12 kWh/m² to a high of 5.8 kWh/m² in June 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
54.3Bright
64.2Bright
74.2Bright
84.1Bright
94.1Bright
104.0Bright
114.0Moderate
123.9Moderate
133.9Moderate
143.8Moderate
153.8Moderate
163.7Moderate
173.7Moderate
183.6Moderate
193.6Moderate
203.5Moderate
213.5Moderate
223.4Moderate
233.4Moderate
243.3Moderate
253.3Moderate
263.3Moderate
273.2Moderate
283.2Moderate
293.1Moderate
303.1Moderate
Planning a trip in September

Is September a good time to visit Cluj-Napoca?

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

6.2
Sightseeing
2nd-best month of the year
3.1
Beach & pool
4th-best month of the year

September is a reasonable time to visit Cluj-Napoca for sightseeing.

What to pack for Cluj-Napoca in September

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

In September, Cluj-Napoca sees daytime highs around 20°C and nights near 9°C. Worth packing: rain gear. About 10 days see rain.

rain gear

UV index in Cluj-Napoca 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 Cluj-Napoca peaks around July 15 at about 8 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near January 1 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 7 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highModerateLowJul 15UV 8Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar3Moderate
Apr7High
May6High
Jun8Very high
Jul8Very high
Aug8Very high
Sep5Moderate
Oct3Moderate
Nov2Low
Dec1Low

Air quality in Cluj-Napoca 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 Cluj-Napoca is worst in April — around 24 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (December, 11 µg/m³).

Seasonal pattern from CAMS reanalysis, scaled to Cluj-Napoca's WHO annual average of 17.8 µg/m³.

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodApr 1624 µg/m³Dec 1511 µg/m³
PM2.5 (µg/m³)Level
Jan15Moderate
Feb17Moderate
Mar22Moderate
Apr24Moderate
May22Moderate
Jun22Moderate
Jul21Moderate
Aug19Moderate
Sep15Moderate
Oct12Moderate
Nov13Moderate
Dec11Good
Location & terrain

Where is Cluj-Napoca?

Cluj-Napoca sits at 46.8°N, 23.6°E, 352 m above sea level, in Romania. The nearest listed city is Turda, 26 km away.

Ocna MureşDejLuduşAiudZalău

Topography around Cluj-Napoca

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

Within 3 km, the terrain around Cluj-Napoca has only modest variations in elevation — a maximum elevation change of 202 m around an average of 375 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 546 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,669 m.

The land around Cluj-Napoca is covered by artificial surfaces (61%) and trees (24%) within 3 km, grassland (45%), trees (25%) and cropland (21%) within 16 km, and trees (43%), grassland (35%) and cropland (20%) within 80 km.

3 km
202 m
16 km
546 m
80 km
1,669 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Turda 26 km · Câmpia Turzii 32 km · Gherla 38 km · Ocna Mureş 47 km · Dej 47 km · Luduş 50 km · Aiud 52 km · Zalău 64 km

Romania travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type C / F
230 V · 50 Hz
Prices
≈ 44% of US
price level, 2025
GDP per capita
$22,538
2025
Happiness
6.6 / 10
World Happiness, 2025
Safe drinking water
82%
of population, 2024
Homicide rate
1.1
per 100k, 2023
Road deaths
10.3
per 100k/yr, 2019
Income group
High
World Bank
English
Very high
EF EPI 605
Religion
Romanian Orthodox 85%other 5%Roman Catholic 5%Reformed 3%

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 Cluj-Napoca (46.7667°, 23.6°, elevation 352 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).