Constanța weather in September

In September, Constanța sees average daytime highs of 22°C and overnight lows near 18°C, with 51 mm of rain across 5.9 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 1st-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 54% 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 Constanța's 4th-clearest and 7th-windiest month. For the whole year in context, see Constanța's year-round climate.

Daytime high
22°
4th warmest
Overnight low
18°
9th coldest
Rainfall
51 mm
5.9 wet days
Daylight
12 h 18 min
5:51 AM – 6:09 PM
Cloud cover
42%
4th clearest
Wind
18 km/h
7th windiest
Solar energy
4.28 kWh/m²
Travel score
7.6
out of 10

Constanța is locality in Constanța County, Romania.

Air quality
Moderate
PM2.5 12.4 µg/m³ · 2018
Founded
~300 BCE

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 Constanța reaches about 22°C in the afternoon and slips back to 18°C overnight — a 4°C spread between the day's warmth and the night's chill. On most days the high lands between 18°C and 25°C. Set against its neighbours, September runs about 4°C cooler than August and about 5°C warmer than October.

10°15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12420
22420
32419
42419
52319
62319
72319
82319
92319
102318
112218
122218
132218
142218
152218
162218
172218
182117
192117
202117
212117
222117
232117
242017
252016
262016
272016
282016
292016
302016

How September really feels in Constanța

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.

Constanța weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 447.33.69.10.0
Feb / 336.22.410.20.2
Mar / 417.81.111.61.5
Apr12° / 336.90.113.23.6
May18° / 14°366.9014.56.4
Jun23° / 19°396.8015.37.7
Jul26° / 21°304.90158.1
Aug26° / 22°314.8013.88.2
Sep22° / 18°515.9012.37.6
Oct17° / 13°506.8010.85.6
Nov11° / 457.10.69.43.0
Dec / 4682.28.70.7

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 54% 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 30%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
17822
27723
37723
47624
57723
67624
77624
87624
97525
107525
117426
127426
137327
147327
157228
167129
177129
186931
196832
206733
216733
226634
236436
246337
256238
266238
276139
286139
296040
305941

Chance of precipitation in September

Any precipitation

Constanța gets around 51 mm of rain over 5.9 wet days in September, the wettest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 19% and peaks near 24% on the wettest days.

0%10%20%30%151015202530
Rain chance (%)
120
220
319
419
518
617
717
816
916
1016
1116
1216
1316
1416
1517
1617
1718
1819
1919
2020
2121
2221
2322
2422
2523
2623
2723
2824
2924
3024

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 34% of days. Sticky, muggy-or-worse air turns up on roughly 12% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1182828242
2192928222
3212928201
4233028181
5243028171
6253028151
7263029141
8273029131
9283029120
10293029120
11293029110
12303028110
13313028100
14323028100
15332928100
1634292890
1735282790
1836282790
1937272790
2039272690
2140262680
2241262580
2342252480
2443252480
2544252380
2645252270
2746252270
2847252170
2948252170
3048252060

Wind in September

Winds average 18 km/h in September.

Across September, daily wind ranges from about 17 km/h on the calmest days to 19 km/h at its breeziest. It stays fairly steady from day to day.

0510152025151015202530
Wind speed (km/h)Feels
117light breeze
217light breeze
317light breeze
417light breeze
517light breeze
617light breeze
717light breeze
818light breeze
918light breeze
1018light breeze
1118light breeze
1218light breeze
1318light breeze
1418light breeze
1518light breeze
1618light breeze
1718light breeze
1818light breeze
1918light breeze
2018light breeze
2118light breeze
2218light breeze
2318light breeze
2419light breeze
2519light breeze
2619light breeze
2719light breeze
2819light breeze
2919light breeze
3019light breeze

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 5:33 AM to 6:08 AM, and sunset from 6:37 PM to 5:42 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.15:336:37
213.05:346:36
313.05:356:34
412.95:376:32
512.95:386:30
612.85:396:28
712.85:406:26
812.75:416:24
912.75:426:22
1012.65:446:20
1112.65:456:18
1212.55:466:17
1312.55:476:15
1412.45:486:13
1512.45:506:11
1612.35:516:09
1712.25:526:07
1812.25:536:05
1912.15:546:03
2012.15:566:01
2112.05:575:59
2212.05:585:57
2311.95:595:55
2411.96:005:53
2511.86:025:51
2611.86:035:49
2711.76:045:48
2811.76:055:46
2911.66:065:44
3011.66:085:42

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.28 kWh/m².

For context, solar energy here swings from a low near 1.24 kWh/m² to a high of 6.71 kWh/m² in July across the year — September's 4.28 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.1Bright
25.0Bright
35.0Bright
44.9Bright
54.9Bright
64.8Bright
74.8Bright
84.7Bright
94.7Bright
104.6Bright
114.6Bright
124.5Bright
134.5Bright
144.4Bright
154.3Bright
164.3Bright
174.2Bright
184.2Bright
194.1Bright
204.0Bright
214.0Moderate
223.9Moderate
233.8Moderate
243.8Moderate
253.7Moderate
263.7Moderate
273.6Moderate
283.5Moderate
293.5Moderate
303.4Moderate
Planning a trip in September

Is September a good time to visit Constanța?

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

7.6
Sightseeing
4th-best month of the year
5.1
Beach & pool
4th-best month of the year

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

What to pack for Constanța in September

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

In September, Constanța sees daytime highs around 22°C and nights near 18°C. Little to plan around — just the basics. About 6 days see rain.

Sea temperature near Constanța in September

The nearest coast averages about 22°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 20 km away) is warmest in August at about 25°C and coldest in February near 6°C.

It's comfortable for a long swim from Jun 12 to Sep 29 — about 3.6 months when the water holds above 20°C.

10°20°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan7Bracing
Feb6Bracing
Mar7Bracing
Apr10Bracing
May16Cool
Jun21Refreshing
Jul24Refreshing
Aug25Warm
Sep22Refreshing
Oct18Cool
Nov14Bracing
Dec10Bracing

UV index in Constanța 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 Constanța peaks around July 18 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 18UV 8Dec 20UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar3Moderate
Apr7High
May6High
Jun8Very high
Jul8Very high
Aug8Very high
Sep6High
Oct3Moderate
Nov2Low
Dec1Low

Air quality in Constanța 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 Constanța is worst in March — around 20 µg/m³ PM2.5 (moderate), about 2.5× the cleanest month (December, 8 µg/m³).

Seasonal pattern from CAMS reanalysis, scaled to Constanța's WHO annual average of 12.4 µg/m³.

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodMar 1719 µg/m³Dec 148 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb13Moderate
Mar20Moderate
Apr14Moderate
May13Moderate
Jun14Moderate
Jul13Moderate
Aug12Moderate
Sep11Good
Oct10Good
Nov9Good
Dec8Good
Location & terrain

Where is Constanța?

Constanța sits at 44.2°N, 28.6°E, 40 m above sea level, in Romania. The nearest listed city is Năvodari, 15 km away.

CernavodăFeteştiFetești-GarăDobrichSlobozia

Topography around Constanța

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

Within 3 km, the terrain around Constanța has only modest variations in elevation — a maximum elevation change of 68 m around an average of 27 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 96 m; within 80 km, significant variations in elevation — a maximum elevation change of 397 m.

The land around Constanța is covered by artificial surfaces (61%) within 3 km, water (51%) and cropland (32%) within 16 km, and cropland (52%) and water (31%) within 80 km.

3 km
68 m
16 km
96 m
80 km
397 m
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
September weather nearby: Năvodari 15 km · Medgidia 29 km · Mangalia 41 km · Cernavodă 51 km · Feteşti 68 km · Fetești-Gară 70 km · Dobrich 94 km · Slobozia 110 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 Constanța (44.1807°, 28.6343°, elevation 40 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).