Piran in Summer
In summer (June, July and August), Piran sees average daytime highs around 25°C and overnight lows near 22°C, with 189 mm of rain over about 20 wet days across the season. It is the warmest season of the year and the driest season of the year.
Over the season highs climb from about 22°C in early June to 25°C by late August. The sky is clear or mostly clear about 58% of the time across summer, and the air most often feels muggy.
Summer is Piran's best season of the year to visit on our travel score. For the whole year in context, see Piran's year-round climate.
- Avg daytime high
- 25°C
- warmest season of the year
- Avg overnight low
- 22°C
- Rainfall
- 189 mm
- 20 wet days
- Avg wind
- 12 km/h
- Travel score
- 7.7
- best season of the year
- Months
- Jun · Jul · Aug
Temperature in Piran in Summer
Over the season highs climb from about 22°C in early June to 25°C by late August.
A typical summer day in Piran reaches about 25°C and drops to 22°C overnight. The warmest of the three months is July, the coolest June.
Piran weather by month
How the three summer months (June, July and August) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 9° / 6° | 83 | 9.9 | 0.1 | 8.9 | 1.7 |
| Feb | 9° / 6° | 85 | 8.9 | 0.6 | 10.1 | 1.7 |
| Mar | 11° / 8° | 75 | 8.4 | 0.3 | 11.6 | 2.8 |
| Apr | 14° / 12° | 75 | 9.3 | 0 | 13.2 | 4.3 |
| May | 19° / 16° | 82 | 9.3 | 0 | 14.7 | 6.3 |
| Jun | 23° / 21° | 64 | 7.3 | 0 | 15.4 | 7.6 |
| Jul | 26° / 23° | 47 | 5.6 | 0 | 15.1 | 7.9 |
| Aug | 26° / 23° | 78 | 7 | 0 | 13.9 | 7.7 |
| Sep | 22° / 19° | 142 | 9.6 | 0 | 12.3 | 6.9 |
| Oct | 18° / 16° | 141 | 12.3 | 0 | 10.7 | 5.7 |
| Nov | 14° / 12° | 170 | 13.9 | 0.1 | 9.3 | 3.6 |
| Dec | 10° / 8° | 116 | 11.3 | 0.4 | 8.6 | 2.3 |
Cloud cover in Summer
The sky is clear or mostly clear about 58% of the time across summer.
Chance of precipitation in Summer
Piran gets around 189 mm of rain over 20 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels muggy — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 12 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 15 h 12 min in early June to 13 h 12 min by late August. The lit band spans sunrise to sunset each day.
Solar energy in Summer
Average shortwave solar energy reaching the ground each day across summer, about 6.2 kWh/m².
Is summer a good time to visit Piran?
Our two travel scores rate summer for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
summer is one of the better times to visit Piran for general sightseeing. The water and warmth also suit a beach or pool day.
What to pack for Piran in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Piran sees daytime highs around 25°C and nights near 22°C. Pack sun protection. Worth having: light clothes. About 20 days see rain.
Sea temperature near Piran in Summer
The nearest coast averages about 24°C across summer — 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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 11 | 10 | 10 | 13 | 18 | 23 | 25 | 25 | 23 | 19 | 16 | 13 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Cool | Refreshing | Warm | Warm | Refreshing | Cool | Cool | Bracing |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 11 | Bracing |
| Feb | 10 | Bracing |
| Mar | 10 | Bracing |
| Apr | 13 | Bracing |
| May | 18 | Cool |
| Jun | 23 | Refreshing |
| Jul | 25 | Warm |
| Aug | 25 | Warm |
| Sep | 23 | Refreshing |
| Oct | 19 | Cool |
| Nov | 16 | Cool |
| Dec | 13 | Bracing |
UV index in Piran in Summer
Clear-sky midday UV across summer averages 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 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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 1 | 2 | 4 | 7 | 7 | 8 | 8 | 7 | 5 | 3 | 2 | 1 |
| Level | Low | Moderate | Moderate | High | High | Very high | Very high | Very high | Moderate | Moderate | Low | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 1 | Low |
| Feb | 2 | Moderate |
| Mar | 4 | Moderate |
| Apr | 7 | High |
| May | 7 | High |
| Jun | 8 | Very high |
| Jul | 8 | Very high |
| Aug | 7 | Very high |
| Sep | 5 | Moderate |
| Oct | 3 | Moderate |
| Nov | 2 | Low |
| Dec | 1 | Low |
Air quality in Piran in Summer
Average fine-particle pollution (PM2.5) through the year — so you can see where summer 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).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 22 | 20 | 20 | 19 | 16 | 16 | 16 | 13 | 12 | 14 | 14 | 18 |
| Level | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 22 | Moderate |
| Feb | 20 | Moderate |
| Mar | 20 | Moderate |
| Apr | 19 | Moderate |
| May | 16 | Moderate |
| Jun | 16 | Moderate |
| Jul | 16 | Moderate |
| Aug | 13 | Moderate |
| Sep | 12 | Moderate |
| Oct | 14 | Moderate |
| Nov | 14 | Moderate |
| Dec | 18 | Moderate |
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.
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.
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
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.