Novo Mesto weather in September

In September, Novo Mesto sees average daytime highs of 21°C and overnight lows near 11°C, with 120 mm of rain across 11.7 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 23°C in the first days to 19°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 06 min at the start of September to 11 h 30 min by month's end. Set against the rest of the year, September is Novo Mesto's 4th-clearest and 10th-windiest month. For the whole year in context, see Novo Mesto's year-round climate.

Daytime high
21°
4th warmest
Overnight low
11°
9th coldest
Rainfall
120 mm
11.7 wet days
Daylight
12 h 18 min
5:44 AM – 6:03 PM
Cloud cover
57%
4th clearest
Wind
6 km/h
10th windiest
Solar energy
3.59 kWh/m²
Travel score
6.2
out of 10

Novo Mesto is town in Lower Carniola, Slovenia.

Air quality
Good
PM10 21.4 µg/m³ · 2019
Density
734/km²
people per km²
Founded
1365

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 19°C by the end.

A typical September day in Novo Mesto 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 5°C warmer than October.

10°15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12313
22313
32313
42313
52213
62213
72212
82212
92212
102212
112112
122112
132112
142111
152111
162111
172011
182011
192011
202011
212011
222010
232010
241910
251910
261910
271910
281910
291910
30189

How September really feels in Novo Mesto

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.

Novo Mesto 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 / -2°609.26.28.90.0
Feb / -2°728.85.610.10.5
Mar11° / 7410.53.811.62.8
Apr16° / 9012113.34.6
May20° / 10°11214.7014.75.7
Jun24° / 14°11513.4015.56.4
Jul26° / 15°10812.2015.26.5
Aug26° / 15°11211.6013.96.7
Sep21° / 11°12011.7012.36.2
Oct15° / 10610.10.610.74.7
Nov10° / 10611.32.99.31.9
Dec / -1°8810.25.28.50.0

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 19% of September, with mostly cloudy or overcast conditions the remaining 49%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15743
25644
35644
45644
55644
65644
75545
85545
95446
105446
115347
125347
135347
145248
155149
165149
175050
185050
194951
204951
214852
224852
234852
244852
254852
264852
274852
284852
294852
304753

Chance of precipitation in September

Any precipitation

Novo Mesto gets around 120 mm of rain over 11.7 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 39% and peaks near 42% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
142
242
342
442
542
642
742
842
942
1042
1141
1241
1341
1440
1540
1640
1739
1839
1938
2038
2137
2237
2336
2436
2536
2636
2736
2836
2936
3037

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 58% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)
13835252
24035232
34236212
44336192
54437181
64537171
74638161
84738151
94738140
104838130
114938120
125038120
135237110
145436100
15563590
16573490
17593380
18623170
19633070
20662860
21672760
22692650
23702550
24722440
25742330
26742330
27762220
28762220
29762220
30772210

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 30 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 96 minutes over September. Sunrise moves from 5:25 AM to 6:02 AM, and sunset from 6:33 PM to 5:35 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.15:256:33
213.15:266:31
313.05:286:29
413.05:296:27
512.95:306:25
612.95:316:23
712.85:336:21
812.85:346:19
912.75:356:17
1012.65:366:15
1112.65:386:13
1212.55:396:11
1312.55:406:09
1412.45:426:07
1512.45:436:05
1612.35:446:03
1712.35:456:01
1812.25:475:59
1912.25:485:57
2012.15:495:55
2112.05:515:53
2212.05:525:51
2311.95:535:49
2411.95:545:47
2511.85:565:45
2611.85:575:43
2711.75:585:41
2811.76:005:39
2911.66:015:37
3011.56:025:35

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.59 kWh/m².

For context, solar energy here swings from a low near 1.06 kWh/m² to a high of 5.92 kWh/m² in July across the year — September's 3.59 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.3Bright
24.2Bright
34.2Bright
44.1Bright
54.1Bright
64.0Bright
74.0Bright
84.0Moderate
93.9Moderate
103.9Moderate
113.8Moderate
123.8Moderate
133.7Moderate
143.7Moderate
153.6Moderate
163.6Moderate
173.5Moderate
183.5Moderate
193.4Moderate
203.4Moderate
213.3Moderate
223.3Moderate
233.3Moderate
243.2Moderate
253.2Moderate
263.1Moderate
273.1Moderate
283.0Moderate
293.0Moderate
303.0Moderate
Planning a trip in September

Is September a good time to visit Novo Mesto?

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

6.2
Sightseeing
4th-best month of the year
3.6
Beach & pool
4th-best month of the year

September is a reasonable time to visit Novo Mesto for sightseeing.

What to pack for Novo Mesto in September

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

In September, Novo Mesto sees daytime highs around 21°C and nights near 11°C. Worth packing: rain gear. About 12 days see rain.

rain gear

UV index in Novo Mesto 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 Novo Mesto peaks around July 15 at about 8 (very high) — sunscreen, a hat and midday shade are essential. 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 highHighModerateLowJul 15UV 8Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb2Moderate
Mar4Moderate
Apr7High
May6High
Jun8Very high
Jul8Very high
Aug7Very high
Sep5High
Oct3Moderate
Nov2Low
Dec1Low

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

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateJan 1919 µg/m³Sep 1613 µg/m³
PM2.5 (µg/m³)Level
Jan19Moderate
Feb17Moderate
Mar19Moderate
Apr18Moderate
May15Moderate
Jun16Moderate
Jul14Moderate
Aug14Moderate
Sep13Moderate
Oct14Moderate
Nov14Moderate
Dec15Moderate
Location & terrain

Where is Novo Mesto?

Novo Mesto sits at 45.8°N, 15.2°E, 187 m above sea level, in Slovenia. The nearest listed city is Žumberak, 20 km away.

ŽumberakTrbovljeSamoborKarlovacCeljeZaprešićLjubljanaVelenje

Topography around Novo Mesto

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

Within 3 km, the terrain around Novo Mesto has only modest variations in elevation — a maximum elevation change of 124 m around an average of 202 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 1,034 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,492 m.

The land around Novo Mesto is covered by trees (47%) and grassland (22%) within 3 km, trees (70%) and grassland (22%) within 16 km, and trees (77%) within 80 km.

3 km
124 m
16 km
1,034 m
80 km
2,492 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Žumberak 20 km · Trbovlje 40 km · Samobor 43 km · Karlovac 46 km · Celje 48 km · Zaprešić 50 km · Ljubljana 58 km · Velenje 62 km

Slovenia travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type C / F
230 V · 50 Hz
Prices
≈ 63% of US
price level, 2025
GDP per capita
$37,376
2025
Happiness
6.9 / 10
World Happiness, 2025
Safe drinking water
100%
of population, 2024
Homicide rate
0.6
per 100k, 2023
Road deaths
5.1
per 100k/yr, 2019
Income group
High
World Bank
Religion
Catholic 69%atheist 14%Orthodox 4%non-believer/agnostic 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 Novo Mesto (45.804°, 15.1689°, elevation 187 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).