Postojna weather in August

In August, Postojna sees average daytime highs of 24°C and overnight lows near 15°C, with 145 mm of rain across 12.4 wet days and about 13.9 hours of daylight. It is the 2nd-warmest and 4th-wettest month of the year here.

Highs ease over the month, from about 25°C in the first days to 22°C by the end. The sky is clear or mostly clear about 46% of the time in August, and the air most often feels comfortable.

Daylight stretches from about 14 h 36 min at the start of August to 13 h 12 min by month's end. Set against the rest of the year, August is Postojna's 2nd-clearest and 12th-windiest month. For the whole year in context, see Postojna's year-round climate.

Daytime high
24°
2nd warmest
Overnight low
15°
11th coldest
Rainfall
145 mm
12.4 wet days
Daylight
14 hours
5:08 AM – 7:06 PM
Cloud cover
47%
2nd clearest
Wind
7 km/h
12th windiest
Solar energy
5.27 kWh/m²
Travel score
6.7
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 August

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 25°C in the first days to 22°C by the end.

A typical August day in Postojna reaches about 24°C in the afternoon and slips back to 15°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 19°C and 29°C. Set against its neighbours, August runs on par with July and about 5°C warmer than September.

10°20°30°151015202531
Avg high (°C)Avg low (°C)
12515
22515
32515
42515
52515
62515
72515
82515
92515
102515
112515
122515
132515
142515
152515
162415
172415
182415
192414
202414
212414
222414
232414
242314
252314
262314
272314
282313
292213
302213
312213

How August really feels in Postojna

Once humidity and wind are folded in, August 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

August 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 August compares with the rest of the year at a glance. August is the 2nd-warmest and 4th-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 August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 46% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 19% of August, with mostly cloudy or overcast conditions the remaining 35%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16733
26733
36733
46733
56832
66832
76832
86832
96733
106733
116733
126733
136733
146733
156634
166634
176733
186634
196634
206535
216436
226436
236337
246238
256139
266139
276040
285941
295842
305743
315743

Chance of precipitation in August

Any precipitation

Postojna gets around 145 mm of rain over 12.4 wet days in August. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 41% and peaks near 43% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
141
241
340
440
540
640
740
840
940
1040
1140
1240
1340
1440
1540
1640
1740
1840
1940
2040
2141
2241
2341
2441
2542
2642
2742
2843
2943
3043
3143

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, August lands in the comfortable band about 42% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
11735445
21735445
31736434
41736424
51737424
61738414
71838404
81839394
91840383
101841383
111941373
121942373
131943362
141944352
151944352
161945342
171945341
181946341
192046331
202046331
212146321
222246311
232346301
242446291
252645281
262845261
273044251
283244231
293543221
303742201
313942191

Wind in August

Winds average 7 km/h in August, the calmest month.

Across August, daily wind ranges from about 7 km/h on the calmest days to 8 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
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
298calm
308calm
318calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 14 h 36 min at the start of August to 13 h 12 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 84 minutes over August. Sunrise moves from 4:50 AM to 5:28 AM, and sunset from 7:28 PM to 6:39 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.64:507:28
214.64:517:27
314.64:527:26
414.54:547:24
514.54:557:23
614.44:567:22
714.44:577:20
814.34:597:19
914.35:007:17
1014.25:017:16
1114.25:027:14
1214.15:037:12
1314.15:057:11
1414.15:067:09
1514.05:077:08
1614.05:087:06
1713.95:107:04
1813.95:117:03
1913.85:127:01
2013.85:146:59
2113.75:156:57
2213.75:166:56
2313.65:176:54
2413.65:196:52
2513.55:206:50
2613.55:216:48
2713.45:226:46
2813.35:246:45
2913.35:256:43
3013.25:266:41
3113.25:286:39

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 5.27 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 — August's 5.27 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.8Bright
25.8Bright
35.8Bright
45.7Bright
55.7Bright
65.7Bright
75.6Bright
85.6Bright
95.6Bright
105.5Bright
115.5Bright
125.5Bright
135.4Bright
145.4Bright
155.3Bright
165.3Bright
175.3Bright
185.2Bright
195.2Bright
205.1Bright
215.1Bright
225.0Bright
235.0Bright
244.9Bright
254.8Bright
264.8Bright
274.7Bright
284.7Bright
294.6Bright
304.5Bright
314.5Bright
Planning a trip in August

Is August a good time to visit Postojna?

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

6.7
Sightseeing
2nd-best month of the year
5.6
Beach & pool
2nd-best month of the year

August is a reasonable time to visit Postojna for sightseeing.

What to pack for Postojna in August

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

In August, Postojna sees daytime highs around 24°C and nights near 15°C. Worth packing: light clothes, rain gear and sun protection. About 12 days see rain.

light clothesrain gearsun protection

Sea temperature near Postojna in August

The nearest coast averages about 23°C in August — 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 August

LowModerateHighVery highExtreme

Clear-sky midday UV in August 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 August

GoodModeratePoorUnhealthyVery unhealthy

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