Postojna weather in January

In January, Postojna sees average daytime highs of 3°C and overnight lows near -3°C, with 90 mm of precipitation across 9.9 wet days and about 8.9 hours of daylight. It is the 12th-warmest and 12th-wettest month of the year here.

Day-to-day highs hold fairly steady near 3°C through the month. The sky is clear or mostly clear about 25% of the time in January, and the air most often feels dry.

Daylight stretches from about 8 h 30 min at the start of January to 9 h 24 min by month's end. Set against the rest of the year, January is Postojna's 10th-clearest and 3rd-windiest month. For the whole year in context, see Postojna's year-round climate.

Daytime high
12th warmest
Overnight low
-3°
1st coldest
Precipitation
90 mm
9.9 wet days
Daylight
8 h 54 min
7:47 AM – 4:38 PM
Cloud cover
67%
10th clearest
Wind
9 km/h
3rd windiest
Solar energy
1.34 kWh/m²
Travel score
0.0
out of 10

Postojna is city in Slovenia.

Density
288/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 3°C through the month.

A typical January day in Postojna reaches about 3°C in the afternoon and slips back to -3°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between -2°C and 8°C. Set against its neighbours, January runs about 1°C cooler than December and about 2°C cooler than February.

-10°-5°10°151015202531
Avg high (°C)Avg low (°C)
14-2
24-2
34-2
44-2
54-2
64-2
74-2
84-2
94-2
104-2
114-2
124-2
134-2
144-2
153-2
163-2
173-2
183-3
193-3
203-3
213-3
223-3
233-3
243-3
253-3
263-3
273-3
283-3
293-3
304-3
314-3

How January really feels in Postojna

Once humidity and wind are folded in, January averages 0 days that feel above 32°C and 31 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
31
wind chill below the day's low

The story in January is cold — wind chill drags the overnight "feels like" below the raw low.

Postojna weather by month

How January compares with the rest of the year at a glance. January is the 12th-warmest and 12th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -3°909.95.38.90.0
Feb / -2°106105.310.10.2
Mar / 10611.13.711.62.0
Apr14° / 12213.71.213.33.7
May18° / 10°14214.8014.75.3
Jun22° / 13°13714.4015.56.1
Jul25° / 15°12212.7015.26.8
Aug24° / 15°14512.4013.96.7
Sep19° / 11°17612.1012.35.8
Oct14° / 14812.10.410.74.0
Nov / 17212.62.39.31.5
Dec / -2°12210.34.48.50.0

Cloud cover in January

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 25% of the time in January.

Beyond those clear spells, partly cloudy skies cover about 10% of January, with mostly cloudy or overcast conditions the remaining 65%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13763
23664
33565
43664
53664
63565
73565
83565
93664
103565
113466
123466
133565
143565
153565
163565
173466
183565
193565
203565
213565
223565
233565
243664
253565
263565
273565
283664
293763
303763
313763

Chance of precipitation in January

Any precipitationSnow

Postojna gets around 90 mm of rain and snow over 9.9 wet days in January, the driest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 32% and peaks near 35% on the wettest days, and about 5 days bring snow.

0%10%20%30%40%50%151015202531
Rain chance (%)Snow chance (%)
13516
23516
33516
43416
53416
63315
73315
83315
93215
103215
113215
123215
133116
143116
153116
163116
173116
183117
193117
203117
213118
223118
233119
243119
253119
263219
273219
283219
293219
303319
313319

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 9 km/h in January.

Across January, daily wind ranges from about 9 km/h on the calmest days to 10 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
19calm
29calm
39calm
49calm
59calm
69calm
79calm
89calm
99calm
109calm
119calm
129calm
139calm
149calm
159calm
169calm
179calm
189calm
199calm
209calm
219calm
229calm
239calm
249calm
259calm
2610calm
2710calm
2810calm
2910calm
3010calm
3110calm

Sunrise & sunset in January

DaylightNight

Daylight runs from about 8 h 30 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 54 minutes over January. Sunrise moves from 7:50 AM to 7:35 AM, and sunset from 4:22 PM to 4:58 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
18.57:504:22
28.57:504:23
38.67:504:24
48.67:504:25
58.67:504:26
68.67:504:27
78.67:504:28
88.77:504:29
98.77:504:30
108.77:494:31
118.77:494:32
128.77:494:33
138.87:484:34
148.87:484:36
158.87:474:37
168.97:474:38
178.97:464:39
188.97:464:40
198.97:454:42
209.07:454:43
219.07:444:44
229.07:434:46
239.17:424:47
249.17:424:48
259.17:414:50
269.27:404:51
279.27:394:52
289.37:384:54
299.37:374:55
309.37:364:57
319.47:354:58

Solar energy in January

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in January, about 1.34 kWh/m².

For context, solar energy here swings from a low near 1.07 kWh/m² to a high of 6.11 kWh/m² in July across the year — January's 1.34 kWh/m² sits near the bottom.

00.511.522.5151015202531
Solar energy (kWh/m²)Level
11.1Dim
21.1Dim
31.1Dim
41.1Dim
51.2Dim
61.2Dim
71.2Dim
81.2Dim
91.2Dim
101.2Dim
111.2Dim
121.3Dim
131.3Dim
141.3Dim
151.3Dim
161.3Dim
171.3Dim
181.4Dim
191.4Dim
201.4Dim
211.4Dim
221.5Dim
231.5Dim
241.5Dim
251.5Dim
261.6Dim
271.6Dim
281.6Dim
291.6Dim
301.7Dim
311.7Dim
Planning a trip in January

Is January a good time to visit Postojna?

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

0.0
Sightseeing
11th-best month of the year
0.0
Beach & pool
8th-best month of the year

January is a weaker month for outdoor sightseeing in Postojna.

What to pack for Postojna in January

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

In January, Postojna sees daytime highs around 3°C and nights near -3°C. Pack a warm layer and a heavy coat. Worth having: rain gear. About 10 days see rain.

a warm layera heavy coatrain gear

Sea temperature near Postojna in January

The nearest coast averages about 10°C in January — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 46 km away) is warmest in August at about 23°C and coldest in February near 10°C.

It's comfortable for a long swim from Jun 10 to Sep 22 — about 3.5 months when the water holds above 20°C.

10°15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan10Bracing
Feb10Bracing
Mar10Bracing
Apr12Bracing
May17Cool
Jun21Refreshing
Jul23Refreshing
Aug23Refreshing
Sep21Refreshing
Oct18Cool
Nov15Cool
Dec12Bracing

UV index in Postojna 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 Postojna peaks around July 16 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 10 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJul 16UV 9Jan 10UV 1
UV index (midday)Level
Jan1Low
Feb2Moderate
Mar5Moderate
Apr7Very high
May7High
Jun8Very high
Jul9Very high
Aug8Very high
Sep5High
Oct3Moderate
Nov2Low
Dec1Low

Air quality in Postojna 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 Postojna 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 1918 µg/m³Sep 1512 µg/m³
PM2.5 (µg/m³)Level
Jan19Moderate
Feb17Moderate
Mar18Moderate
Apr18Moderate
May15Moderate
Jun16Moderate
Jul14Moderate
Aug13Moderate
Sep12Good
Oct13Moderate
Nov13Moderate
Dec15Moderate
Location & terrain

Where is Postojna?

Postojna sits at 45.8°N, 14.2°E, 0 m above sea level, in Slovenia. The nearest listed city is Divača, 21 km away.

DivačaTriesteLjubljanaKoperNova GoricaGoriziaKranjRijeka

Topography around Postojna

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

Within 3 km, the terrain around Postojna has significant variations in elevation — a maximum elevation change of 409 m around an average of 606 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 1,054 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,695 m.

The land around Postojna is covered by trees (69%) and grassland (20%) within 3 km, trees (77%) within 16 km, and trees (70%) within 80 km.

3 km
409 m
16 km
1,054 m
80 km
2,695 m
treesgrasslandcroplandartificial surfaceswaterwetland
January weather nearby: Divača 21 km · Trieste 37 km · Ljubljana 38 km · Koper 45 km · Nova Gorica 48 km · Gorizia 50 km · Kranj 53 km · Rijeka 53 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 Postojna (45.7743°, 14.2153°, 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).