Trnava weather in September

In September, Trnava sees average daytime highs of 21°C and overnight lows near 11°C, with 65 mm of rain across 8.9 wet days and about 12.4 hours of daylight. It is the 4th-warmest and 4th-wettest month of the year here.

Highs ease over the month, from about 23°C in the first days to 18°C by the end. The sky is clear or mostly clear about 33% 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 Trnava's 3rd-clearest and 9th-windiest month. For the whole year in context, see Trnava's year-round climate.

Daytime high
21°
4th warmest
Overnight low
11°
9th coldest
Rainfall
65 mm
8.9 wet days
Daylight
12 h 18 min
5:34 AM – 5:54 PM
Cloud cover
56%
3rd clearest
Wind
11 km/h
9th windiest
Solar energy
3.49 kWh/m²
Travel score
6.6
out of 10

Trnava is city in Slovakia.

Air quality
Elevated
PM2.5 16.2 µg/m³ · 2019
Density
878/km²
people per km²
Founded
1211

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 23°C in the first days to 18°C by the end.

A typical September day in Trnava reaches about 21°C in the afternoon and slips back to 11°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 15°C and 26°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)
12413
22313
32313
42313
52313
62313
72213
82212
92212
102212
112212
122112
132112
142112
152111
162111
172111
182011
192011
202011
212010
222010
231910
241910
251910
261910
271910
281910
29189
30189

How September really feels in Trnava

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.

Trnava weather by month

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

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -3°378.54.68.60.0
Feb / -2°347.83.89.90.2
Mar10° / 418.9211.62.2
Apr16° / 428.30.313.45.1
May21° / 10°6611.30156.2
Jun24° / 14°7611.4015.86.6
Jul26° / 16°8111.5015.56.5
Aug26° / 15°659.8014.16.8
Sep21° / 11°658.9012.46.6
Oct15° / 488.60.110.64.4
Nov / 479.2291.4
Dec / -2°4293.58.20.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 33% 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 49%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15743
25743
35644
45644
55545
65446
75347
85347
95347
105248
115248
125050
135050
145050
154951
164951
174951
184951
194951
204951
214951
224852
234852
244951
254951
264852
274753
284753
294654
304654

Chance of precipitation in September

Any precipitation

Trnava gets around 65 mm of rain over 8.9 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 30% and peaks near 32% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
132
232
332
432
532
632
732
832
931
1031
1131
1231
1330
1430
1530
1630
1730
1830
1929
2029
2129
2228
2328
2428
2528
2628
2728
2829
2929
3029

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 78% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
162299
264288
365287
466277
568266
668266
768266
870255
970255
1072244
1172244
1274233
1375223
1477212
1578202
1679192
1780182
1881172
1983161
2085141
2186131
2287121
2388111
2489101
2589101
269091
279091
289091
299091
309091

Wind in September

Winds average 11 km/h in September.

Across September, daily wind ranges from about 11 km/h on the calmest days to 11 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
111calm
211calm
311calm
411calm
511calm
611calm
711calm
811calm
911calm
1011calm
1111calm
1211calm
1311calm
1411calm
1511calm
1611calm
1711calm
1811calm
1911calm
2011calm
2111calm
2211calm
2311calm
2411calm
2511calm
2611calm
2711calm
2811calm
2911calm
3011calm

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 5:12 AM to 5:54 AM, and sunset from 6:27 PM to 5:24 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.25:126:27
213.25:136:25
313.15:156:22
413.15:166:20
513.05:186:18
612.95:196:16
712.95:216:14
812.85:226:12
912.85:236:10
1012.75:256:07
1112.65:266:05
1212.65:286:03
1312.55:296:01
1412.55:315:59
1512.45:325:57
1612.35:345:54
1712.35:355:52
1812.25:365:50
1912.25:385:48
2012.15:395:46
2112.05:415:43
2212.05:425:41
2311.95:445:39
2411.95:455:37
2511.85:475:35
2611.75:485:33
2711.75:505:30
2811.65:515:28
2911.65:525:26
3011.55:545:24

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.49 kWh/m².

For context, solar energy here swings from a low near 0.84 kWh/m² to a high of 5.82 kWh/m² in June across the year — September's 3.49 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.2Bright
24.1Bright
34.1Bright
44.0Bright
54.0Moderate
63.9Moderate
73.9Moderate
83.8Moderate
93.8Moderate
103.8Moderate
113.7Moderate
123.7Moderate
133.6Moderate
143.6Moderate
153.5Moderate
163.5Moderate
173.4Moderate
183.4Moderate
193.3Moderate
203.3Moderate
213.2Moderate
223.2Moderate
233.1Moderate
243.1Moderate
253.1Moderate
263.0Moderate
273.0Moderate
282.9Moderate
292.9Moderate
302.8Moderate
Planning a trip in September

Is September a good time to visit Trnava?

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

6.6
Sightseeing
2nd-best month of the year
3.9
Beach & pool
4th-best month of the year

September is a reasonable time to visit Trnava for sightseeing.

What to pack for Trnava in September

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

In September, Trnava sees daytime highs around 21°C and nights near 11°C. Worth packing: rain gear. About 9 days see rain.

rain gear

UV index in Trnava in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 4 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Trnava peaks around July 11 at about 8 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 22 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 highHighModerateLowJul 11UV 8Dec 22UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar4Moderate
Apr6High
May6High
Jun7Very high
Jul8Very high
Aug6High
Sep4Moderate
Oct3Moderate
Nov1Low
Dec1Low

Air quality in Trnava 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 Trnava is worst in June — around 19 µg/m³ PM2.5 (moderate), and holds fairly steady the rest of the year.

Seasonal pattern from CAMS reanalysis, scaled to Trnava's WHO annual average of 16.2 µg/m³.

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateJun 1519 µg/m³Dec 1213 µg/m³
PM2.5 (µg/m³)Level
Jan14Moderate
Feb14Moderate
Mar19Moderate
Apr19Moderate
May18Moderate
Jun19Moderate
Jul18Moderate
Aug17Moderate
Sep15Moderate
Oct14Moderate
Nov13Moderate
Dec13Moderate
Location & terrain

Where is Trnava?

Trnava sits at 48.4°N, 17.6°E, 147 m above sea level, in Slovakia. The nearest listed city is Sereď, 15 km away.

PezinokPiešťanyŠaľaSenica

Topography around Trnava

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

Within 3 km, the terrain around Trnava has only modest variations in elevation — a maximum elevation change of 31 m around an average of 151 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 428 m; within 80 km, large variations in elevation — a maximum elevation change of 1,154 m.

The land around Trnava is covered by cropland (42%) and artificial surfaces (36%) within 3 km, cropland (78%) within 16 km, and cropland (54%) and trees (30%) within 80 km.

3 km
31 m
16 km
428 m
80 km
1,154 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Sereď 15 km · Hlohovec 17 km · Senec 22 km · Galanta 23 km · Pezinok 26 km · Piešťany 30 km · Šaľa 33 km · Senica 37 km

Slovakia travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type C / E / F
230 V · 50 Hz
Prices
≈ 58% of US
price level, 2025
GDP per capita
$28,544
2025
Happiness
6.3 / 10
World Happiness, 2025
Safe drinking water
100%
of population, 2024
Homicide rate
1.1
per 100k, 2023
Road deaths
6.1
per 100k/yr, 2019
Income group
High
World Bank
English
Very high
EF EPI 606
Religion
Roman Catholic 56%none 24%Evangelical Church of the Augsburg Confession 5%Greek Catholic 4%

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 Trnava (48.3777°, 17.586°, elevation 147 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).