Koper weather in March

In March, Koper sees average daytime highs of 12°C and overnight lows near 6°C, with 86 mm of precipitation across 9.3 wet days and about 11.6 hours of daylight. It is the 9th-warmest and 8th-wettest month of the year here.

Highs climb over the month, from about 10°C in the first days to 13°C by the end. The sky is clear or mostly clear about 40% of the time in March, and the air most often feels dry.

Daylight stretches from about 10 h 48 min at the start of March to 12 h 24 min by month's end. Set against the rest of the year, March is Koper's 6th-clearest and 2nd-windiest month. For the whole year in context, see Koper's year-round climate.

Daytime high
12°
9th warmest
Overnight low
4th coldest
Precipitation
86 mm
9.3 wet days
Daylight
11 h 36 min
6:27 AM – 6:03 PM
Cloud cover
53%
6th clearest
Wind
11 km/h
2nd windiest
Solar energy
3.61 kWh/m²
Travel score
3.3
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 March

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 10°C in the first days to 13°C by the end.

A typical March day in Koper reaches about 12°C in the afternoon and slips back to 6°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 8°C and 16°C. Set against its neighbours, March runs about 3°C warmer than February and about 4°C cooler than April.

10°15°20°151015202531
Avg high (°C)Avg low (°C)
1104
2104
3104
4104
5115
6115
7115
8115
9115
10115
11115
12125
13125
14126
15126
16126
17126
18126
19126
20126
21136
22136
23136
24137
25137
26137
27137
28137
29137
30147
31147

How March really feels in Koper

Once humidity and wind are folded in, March 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

March 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 March compares with the rest of the year at a glance. March is the 9th-warmest and 8th-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 March

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 40% of the time in March.

Beyond those clear spells, partly cloudy skies cover about 15% of March, with mostly cloudy or overcast conditions the remaining 45%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15050
25050
35248
45248
55347
65446
75545
85644
95743
105842
115941
126040
136040
146040
156040
166040
175941
185842
195842
205743
215545
225545
235545
245347
255347
265248
275248
285248
295248
305248
315248

Chance of precipitation in March

Any precipitationSnow

Koper gets around 86 mm of rain and snow over 9.3 wet days in March. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 29% and peaks near 35% on the wettest days, and about 1 day brings snow.

0%10%20%30%40%50%151015202531
Rain chance (%)Snow chance (%)
1345
2334
3334
4324
5324
6313
7303
8293
9283
10263
11262
12252
13242
14242
15242
16242
17252
18252
19262
20272
21282
22292
23302
24311
25321
26331
27331
28341
29351
30351
31351

Humidity in March

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, March lands in the dry band about 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)
1100
2100
3100
4100
5100
6100
7100
8100
9100
10100
11100
12100
13100
14100
15100
16100
17100
18100
19100
20100
21100
22100
23100
24100
25100
26100
27100
28100
29100
30100
31100

Wind in March

Winds average 11 km/h in March.

Across March, 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.

051015151015202531
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
3111calm

Sunrise & sunset in March

DaylightNight

Daylight runs from about 10 h 48 min at the start of March to 12 h 24 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 96 minutes over March. Sunrise moves from 6:54 AM to 5:57 AM, and sunset from 5:42 PM to 6:23 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
110.86:545:42
210.86:535:44
310.96:515:45
411.06:495:46
511.06:475:48
611.16:455:49
711.16:445:51
811.26:425:52
911.26:405:53
1011.36:385:55
1111.36:365:56
1211.46:345:57
1311.46:325:59
1411.56:306:00
1511.56:296:01
1611.66:276:03
1711.76:256:04
1811.76:236:06
1911.86:216:07
2011.86:196:08
2111.96:176:10
2211.96:156:11
2312.06:136:12
2412.06:116:14
2512.16:096:15
2612.26:076:16
2712.26:056:18
2812.36:036:19
2912.36:016:20
3012.45:596:21
3112.45:576:23

Solar energy in March

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in March, about 3.61 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 — March's 3.61 kWh/m² falls in the middle.

012345151015202531
Solar energy (kWh/m²)Level
12.9Moderate
23.0Moderate
33.0Moderate
43.1Moderate
53.1Moderate
63.2Moderate
73.2Moderate
83.3Moderate
93.4Moderate
103.4Moderate
113.5Moderate
123.5Moderate
133.6Moderate
143.6Moderate
153.6Moderate
163.7Moderate
173.7Moderate
183.8Moderate
193.8Moderate
203.8Moderate
213.9Moderate
223.9Moderate
233.9Moderate
244.0Moderate
254.0Bright
264.0Bright
274.1Bright
284.1Bright
294.2Bright
304.2Bright
314.3Bright
Planning a trip in March

Is March a good time to visit Koper?

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

3.3
Sightseeing
8th-best month of the year
0.0
Beach & pool
9th-best month of the year

March is a weaker month for outdoor sightseeing in Koper.

What to pack for Koper in March

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

In March, Koper sees daytime highs around 12°C and nights near 6°C. Pack a warm layer. Worth having: rain gear. About 9 days see rain.

a warm layerrain gear

Sea temperature near Koper in March

The nearest coast averages about 10°C in March — 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 March

LowModerateHighVery highExtreme

Clear-sky midday UV in March 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 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 March

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where March 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
March 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).