Postojna weather in June

In June, Postojna sees average daytime highs of 22°C and overnight lows near 13°C, with 137 mm of rain across 14.4 wet days and about 15.5 hours of daylight. It is the 3rd-warmest and 6th-wettest month of the year here.

Highs climb over the month, from about 21°C in the first days to 24°C by the end. The sky is clear or mostly clear about 35% of the time in June, and the air most often feels dry.

Daylight stretches from about 15 h 12 min at the start of June to 15 h 30 min by month's end. Set against the rest of the year, June is Postojna's 3rd-clearest and 10th-windiest month. For the whole year in context, see Postojna's year-round climate.

Daytime high
22°
3rd warmest
Overnight low
13°
10th coldest
Rainfall
137 mm
14.4 wet days
Daylight
15 h 30 min
4:18 AM – 7:48 PM
Cloud cover
54%
3rd clearest
Wind
7 km/h
10th windiest
Solar energy
6.1 kWh/m²
Travel score
6.1
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 June

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 21°C in the first days to 24°C by the end.

A typical June day in Postojna reaches about 22°C in the afternoon and slips back to 13°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 17°C and 28°C. Set against its neighbours, June runs about 4°C warmer than May and about 2°C cooler than July.

10°15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12111
22112
32112
42112
52112
62112
72212
82212
92213
102213
112213
122213
132213
142213
152313
162313
172313
182314
192314
202314
212314
222314
232314
242314
252314
262414
272414
282414
292414
302414

How June really feels in Postojna

Once humidity and wind are folded in, June 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

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

Postojna weather by month

How June compares with the rest of the year at a glance. June is the 3rd-warmest and 6th-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 June

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 35% of the time in June.

Beyond those clear spells, partly cloudy skies cover about 20% of June, with mostly cloudy or overcast conditions the remaining 45%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14951
24951
34852
44852
54852
64951
75050
85050
95050
105248
115248
125446
135446
145545
155545
165644
175743
185743
195743
205842
215842
225842
235941
246040
256040
266139
276139
286139
296238
306337

Chance of precipitation in June

Any precipitation

Postojna gets around 137 mm of rain over 14.4 wet days in June. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 48% and peaks near 52% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
150
250
351
451
552
652
752
852
952
1051
1151
1250
1350
1449
1549
1648
1748
1847
1946
2046
2145
2244
2344
2443
2543
2643
2743
2843
2943
3043

Humidity in June

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, June lands in the dry band about 43% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)
1633340
2613540
3583750
4563860
5544060
6524170
7504280
8484390
94644100
104544110
114444120
124344130
134244140
144243150
154143160
164142170
174041180
184041190
193940201
203940211
213839221
223739231
233639241
243639251
253539261
263438261
273339271
283239281
293139282
303039292

Wind in June

Winds average 7 km/h in June.

Across June, daily wind ranges from about 7 km/h on the calmest days to 7 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm

Sunrise & sunset in June

DaylightNight

Daylight runs from about 15 h 12 min at the start of June to 15 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 18 minutes over June. Sunrise moves from 4:23 AM to 4:22 AM, and sunset from 7:38 PM to 7:51 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
115.24:237:38
215.34:237:39
315.34:227:40
415.34:227:41
515.34:217:41
615.44:217:42
715.44:207:43
815.44:207:44
915.44:207:44
1015.44:197:45
1115.44:197:46
1215.54:197:46
1315.54:197:47
1415.54:197:47
1515.54:187:48
1615.54:187:48
1715.54:187:49
1815.54:187:49
1915.54:187:50
2015.54:197:50
2115.54:197:50
2215.54:197:50
2315.54:197:51
2415.54:197:51
2515.54:207:51
2615.54:207:51
2715.54:207:51
2815.54:217:51
2915.54:217:51
3015.54:227:51

Solar energy in June

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in June, about 6.1 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 — June's 6.1 kWh/m² sits near the top of that range.

0246151015202530
Solar energy (kWh/m²)Level
15.9Bright
25.9Bright
35.9Bright
46.0Bright
56.0Bright
66.0Bright
76.0Intense
86.0Intense
96.0Intense
106.0Intense
116.1Intense
126.1Intense
136.1Intense
146.1Intense
156.1Intense
166.1Intense
176.1Intense
186.1Intense
196.2Intense
206.2Intense
216.2Intense
226.2Intense
236.2Intense
246.2Intense
256.2Intense
266.2Intense
276.2Intense
286.2Intense
296.2Intense
306.2Intense
Planning a trip in June

Is June a good time to visit Postojna?

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

6.1
Sightseeing
3rd-best month of the year
4.5
Beach & pool
3rd-best month of the year

June is a reasonable time to visit Postojna for sightseeing.

What to pack for Postojna in June

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

In June, Postojna sees daytime highs around 22°C and nights near 13°C. Pack rain gear and sun protection. Worth having: light clothes. About 14 days see rain.

rain gearsun protectionlight clothes

Sea temperature near Postojna in June

The nearest coast averages about 21°C in June — 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 June

LowModerateHighVery highExtreme

Clear-sky midday UV in June peaks around 8 — enough to warrant sun protection. 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 June

GoodModeratePoorUnhealthyVery unhealthy

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