Piran weather in January

In January, Piran sees average daytime highs of 9°C and overnight lows near 6°C, with 83 mm of precipitation across 9.9 wet days and about 8.9 hours of daylight. It is the 11th-warmest and 6th-wettest month of the year here.

Day-to-day highs hold fairly steady near 9°C through the month. The sky is clear or mostly clear about 33% of the time in January, and the air most often feels dry.

Daylight stretches from about 8 h 36 min at the start of January to 9 h 24 min by month's end. Set against the rest of the year, January is Piran's 10th-clearest and 6th-windiest month. For the whole year in context, see Piran's year-round climate.

Daytime high
11th warmest
Overnight low
2nd coldest
Precipitation
83 mm
9.9 wet days
Daylight
8 h 54 min
7:49 AM – 4:41 PM
Cloud cover
60%
10th clearest
Wind
14 km/h
6th windiest
Solar energy
1.45 kWh/m²
Travel score
1.7
out of 10

Piran is coastal town of Slovenia.

Density
94/km²
people per km²

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

Temperature in January

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 9°C through the month.

A typical January day in Piran reaches about 9°C in the afternoon and slips back to 6°C overnight — a 2°C spread between the day's warmth and the night's chill. On most days the high lands between 5°C and 11°C. Set against its neighbours, January runs about 1°C cooler than December and on par with February.

10°15°151015202531
Avg high (°C)Avg low (°C)
197
297
397
497
597
697
797
897
997
1097
1197
1297
1397
1497
1597
1697
1796
1896
1996
2096
2186
2286
2386
2486
2586
2686
2786
2886
2986
3086
3186

Piran weather by month

How January compares with the rest of the year at a glance. January is the 11th-warmest and 6th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 839.90.18.91.7
Feb / 858.90.610.11.7
Mar11° / 758.40.311.62.8
Apr14° / 12°759.3013.24.3
May19° / 16°829.3014.76.3
Jun23° / 21°647.3015.47.6
Jul26° / 23°475.6015.17.9
Aug26° / 23°787013.97.7
Sep22° / 19°1429.6012.36.9
Oct18° / 16°14112.3010.75.7
Nov14° / 12°17013.90.19.33.6
Dec10° / 11611.30.48.62.3

Cloud cover in January

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 33% of the time in January.

Beyond those clear spells, partly cloudy skies cover about 11% of January, with mostly cloudy or overcast conditions the remaining 56%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14456
24555
34555
44555
54555
64555
74654
84654
94654
104555
114555
124456
134555
144456
154555
164456
174456
184456
194456
204456
214357
224357
234258
244258
254258
264258
274258
284258
294258
304357
314357

Chance of precipitation in January

Any precipitation

Piran gets around 83 mm of rain and snow over 9.9 wet days in January. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 33% and peaks near 36% on the wettest days, and about 0 day brings snow.

0%10%20%30%40%50%151015202531
Rain chance (%)
136
236
336
435
535
635
735
834
934
1034
1134
1233
1333
1433
1532
1632
1731
1831
1930
2030
2130
2230
2330
2430
2530
2631
2731
2831
2932
3032
3133

Humidity in January

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, January 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 January

Winds average 14 km/h in January.

Across January, daily wind ranges from about 14 km/h on the calmest days to 15 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
114light breeze
214light breeze
314light breeze
414light breeze
514light breeze
614light breeze
714light breeze
814light breeze
914light breeze
1014light breeze
1114light breeze
1214light breeze
1314light breeze
1414light breeze
1514light breeze
1614light breeze
1714light breeze
1814light breeze
1915light breeze
2015light breeze
2115light breeze
2215light breeze
2315light breeze
2415light breeze
2515light breeze
2615light breeze
2715light breeze
2815light breeze
2915light breeze
3015light breeze
3115light breeze

Sunrise & sunset in January

DaylightNight

Daylight runs from about 8 h 36 min at the start of January to 9 h 24 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 48 minutes over January. Sunrise moves from 7:52 AM to 7:37 AM, and sunset from 4:26 PM to 5:01 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
18.67:524:26
28.67:524:27
38.67:524:28
48.67:524:29
58.67:524:29
68.67:524:30
78.77:524:31
88.77:514:32
98.77:514:33
108.77:514:35
118.77:514:36
128.87:504:37
138.87:504:38
148.87:504:39
158.97:494:40
168.97:494:41
178.97:484:43
188.97:484:44
199.07:474:45
209.07:464:46
219.07:464:48
229.17:454:49
239.17:444:50
249.17:434:52
259.27:434:53
269.27:424:54
279.27:414:56
289.37:404:57
299.37:394:58
309.47:385:00
319.47:375:01

Solar energy in January

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in January, about 1.45 kWh/m².

For context, solar energy here swings from a low near 1.2 kWh/m² to a high of 6.52 kWh/m² in July across the year — January's 1.45 kWh/m² sits near the bottom.

00.511.522.5151015202531
Solar energy (kWh/m²)Level
11.2Dim
21.2Dim
31.3Dim
41.3Dim
51.3Dim
61.3Dim
71.3Dim
81.3Dim
91.3Dim
101.3Dim
111.4Dim
121.4Dim
131.4Dim
141.4Dim
151.4Dim
161.4Dim
171.5Dim
181.5Dim
191.5Dim
201.5Dim
211.5Dim
221.6Dim
231.6Dim
241.6Dim
251.6Dim
261.7Dim
271.7Dim
281.7Dim
291.7Dim
301.8Dim
311.8Dim
Planning a trip in January

Is January a good time to visit Piran?

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

1.7
Sightseeing
11th-best month of the year
0.0
Beach & pool
9th-best month of the year

January is a weaker month for outdoor sightseeing in Piran.

What to pack for Piran in January

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

In January, Piran sees daytime highs around 9°C and nights near 6°C. Pack a warm layer. Worth having: rain gear. About 10 days see rain.

a warm layerrain gear

Sea temperature near Piran in January

The nearest coast averages about 11°C in January — 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 Piran in January

LowModerateHighVery highExtreme

Clear-sky midday UV in January peaks around 1. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Piran 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 Piran in January

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Piran 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 Piran?

Piran sits at 45.5°N, 13.6°E, 0 m above sea level, in Slovenia. The nearest listed city is Koper, 13 km away.

TriesteMonfalconeDivačaGoriziaNova GoricaPostojna

Topography around Piran

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

Within 3 km, the terrain around Piran has only modest variations in elevation — a maximum elevation change of 172 m around an average of 10 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 412 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,859 m.

The land around Piran is covered by water (82%) within 3 km, water (65%) and trees (20%) within 16 km, and trees (43%) and water (31%) within 80 km.

3 km
172 m
16 km
412 m
80 km
1,859 m
treesshrubsgrasslandcroplandartificial surfaceswater
January weather nearby: Koper 13 km · Trieste 21 km · Monfalcone 31 km · Divača 36 km · Gorizia 46 km · Nova Gorica 48 km · Rovinj 50 km · Postojna 57 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 Piran (45.5278°, 13.5706°, elevation 0 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).