Koper weather in October

In October, Koper sees average daytime highs of 18°C and overnight lows near 12°C, with 157 mm of rain across 12.2 wet days and about 10.7 hours of daylight. It is the 6th-warmest and 2nd-wettest month of the year here.

Highs ease over the month, from about 20°C in the first days to 16°C by the end. The sky is clear or mostly clear about 37% of the time in October, and the air most often feels dry.

Daylight stretches from about 11 h 30 min at the start of October to 9 h 54 min by month's end. Set against the rest of the year, October is Koper's 7th-clearest and 5th-windiest month. For the whole year in context, see Koper's year-round climate.

Daytime high
18°
6th warmest
Overnight low
12°
7th coldest
Rainfall
157 mm
12.2 wet days
Daylight
10 h 42 min
6:29 AM – 5:11 PM
Cloud cover
53%
7th clearest
Wind
11 km/h
5th windiest
Solar energy
2.6 kWh/m²
Travel score
5.5
out of 10

Koper is city in southwest Slovenia.

Air quality
Good
PM10 16.8 µg/m³ · 2019
Density
1,981/km²
people per km²

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in October

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 20°C in the first days to 16°C by the end.

A typical October day in Koper reaches about 18°C in the afternoon and slips back to 12°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 14°C and 21°C. Set against its neighbours, October runs about 5°C cooler than September and about 5°C warmer than November.

10°15°20°25°151015202531
Avg high (°C)Avg low (°C)
12014
22014
32014
41914
51913
61913
71913
81913
91913
101813
111812
121812
131812
141812
151812
161712
171711
181711
191711
201711
211711
221611
231611
241611
251611
261610
271610
281610
291610
301510
311510

How October really feels in Koper

Once humidity and wind are folded in, October 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

October sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Koper weather by month

How October compares with the rest of the year at a glance. October is the 6th-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 779.10.98.91.1
Feb / 858.51.510.11.6
Mar12° / 869.30.711.63.3
Apr16° / 9511.20.213.24.8
May20° / 14°10311.7014.76.2
Jun24° / 18°8510.1015.47.0
Jul27° / 20°628.2015.17.2
Aug27° / 20°898.5013.97.1
Sep22° / 16°14710.3012.36.8
Oct18° / 12°15712.2010.75.5
Nov12° / 16712.70.39.33.1
Dec / 1129.90.98.61.5

Cloud cover in October

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 37% of the time in October.

Beyond those clear spells, partly cloudy skies cover about 16% of October, with mostly cloudy or overcast conditions the remaining 47%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15446
25446
35545
45446
55446
65545
75545
85545
95644
105644
115545
125644
135644
145644
155545
165545
175545
185545
195545
205347
215347
225347
235149
245149
255050
264852
274852
284753
294753
304654
314456

Chance of precipitation in October

Any precipitation

Koper gets around 157 mm of rain over 12.2 wet days in October. 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 41% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
140
241
341
441
541
641
740
840
940
1039
1138
1238
1337
1437
1537
1637
1737
1837
1937
2037
2137
2237
2338
2438
2538
2638
2739
2839
2940
3040
3141

Humidity in October

DryComfortableHumidMuggyOppressiveMiserable

Most of October feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, October lands in the dry band about 71% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
15232151
25232151
35531140
45531140
55730130
65929120
76028120
86227110
96426100
10662590
11672490
12692380
13722170
14732070
15742060
16751960
17761950
18771850
19771850
20781840
21791740
22791740
23791740
24801640
25811630
26811630
27821530
28821530
29821530
30841420
31851320

Wind in October

Winds average 11 km/h in October.

Across October, daily wind ranges from about 10 km/h on the calmest days to 11 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
110calm
210calm
310calm
410calm
510calm
610calm
710calm
810calm
910calm
1010calm
1110calm
1210calm
1310calm
1410calm
1510calm
1610calm
1710calm
1810calm
1910calm
2011calm
2111calm
2211calm
2311calm
2411calm
2511calm
2611calm
2711calm
2811calm
2911calm
3011calm
3111calm

Sunrise & sunset in October

DaylightNight

Daylight runs from about 11 h 30 min at the start of October to 9 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 96 minutes over October. Sunrise moves from 6:09 AM to 6:50 AM, and sunset from 5:39 PM to 4:47 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.56:095:39
211.46:115:37
311.46:125:35
411.36:135:33
511.36:155:31
611.26:165:29
711.26:175:27
811.16:195:25
911.16:205:24
1011.06:215:22
1111.06:235:20
1210.96:245:18
1310.86:255:16
1410.86:275:14
1510.76:285:13
1610.76:295:11
1710.66:315:09
1810.66:325:07
1910.56:345:06
2010.56:355:04
2110.46:365:02
2210.46:385:01
2310.36:394:59
2410.36:414:57
2510.26:424:56
2610.26:434:54
2710.16:454:53
2810.16:464:51
2910.06:484:50
3010.06:494:48
319.96:504:47

Solar energy in October

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in October, about 2.6 kWh/m².

For context, solar energy here swings from a low near 1.2 kWh/m² to a high of 6.47 kWh/m² in July across the year — October's 2.6 kWh/m² falls in the middle.

01234151015202531
Solar energy (kWh/m²)Level
13.2Moderate
23.2Moderate
33.1Moderate
43.1Moderate
53.0Moderate
63.0Moderate
73.0Moderate
82.9Moderate
92.9Moderate
102.8Moderate
112.8Moderate
122.8Moderate
132.7Moderate
142.7Moderate
152.7Moderate
162.6Moderate
172.6Moderate
182.6Moderate
192.5Moderate
202.5Moderate
212.4Moderate
222.4Moderate
232.4Moderate
242.3Moderate
252.3Moderate
262.2Moderate
272.2Moderate
282.1Moderate
292.1Moderate
302.1Moderate
312.0Moderate
Planning a trip in October

Is October a good time to visit Koper?

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

5.5
Sightseeing
6th-best month of the year
1.6
Beach & pool
6th-best month of the year

October is a reasonable time to visit Koper for sightseeing.

What to pack for Koper in October

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

In October, Koper sees daytime highs around 18°C and nights near 12°C. Worth packing: rain gear. About 12 days see rain.

rain gear

Sea temperature near Koper in October

The nearest coast averages about 19°C in October — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore is warmest in August at about 25°C and coldest in February near 10°C.

It's comfortable for a long swim from May 31 to Oct 9 — about 4.3 months when the water holds above 20°C.

10°20°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan11Bracing
Feb10Bracing
Mar10Bracing
Apr13Bracing
May18Cool
Jun23Refreshing
Jul25Warm
Aug25Warm
Sep23Refreshing
Oct19Cool
Nov16Cool
Dec13Bracing

UV index in Koper in October

LowModerateHighVery highExtreme

Clear-sky midday UV in October peaks around 3. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Koper 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
May7High
Jun8Very high
Jul8Very high
Aug7Very high
Sep5Moderate
Oct3Moderate
Nov2Low
Dec1Low

Air quality in Koper in October

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where October falls, not just the annual average.

Air quality in Koper is worst in January — around 22 µg/m³ PM2.5 (moderate), about 1.8× the cleanest month (September, 12 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateJan 1822 µg/m³Sep 1412 µg/m³
PM2.5 (µg/m³)Level
Jan22Moderate
Feb20Moderate
Mar20Moderate
Apr19Moderate
May16Moderate
Jun16Moderate
Jul16Moderate
Aug13Moderate
Sep12Moderate
Oct14Moderate
Nov14Moderate
Dec18Moderate
Location & terrain

Where is Koper?

Koper sits at 45.5°N, 13.7°E, 12 m above sea level, in Slovenia. The nearest listed city is Trieste, 12 km away.

DivačaMonfalconeGoriziaPostojnaNova Gorica

Topography around Koper

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

Within 3 km, the terrain around Koper has only modest variations in elevation — a maximum elevation change of 238 m around an average of 24 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 575 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,150 m.

The land around Koper is covered by water (34%) and artificial surfaces (23%) within 3 km, trees (46%) and water (34%) within 16 km, and trees (48%) and water (29%) within 80 km.

3 km
238 m
16 km
575 m
80 km
2,150 m
treesshrubsgrasslandcroplandartificial surfaceswaterwetland
October weather nearby: Trieste 12 km · Piran 13 km · Divača 24 km · Monfalcone 32 km · Gorizia 44 km · Postojna 45 km · Nova Gorica 46 km · Rovinj 52 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 Koper (45.5482°, 13.7296°, elevation 12 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).