Piran in Fall

In fall (September, October and November), Piran sees average daytime highs around 18°C and overnight lows near 15°C, with 454 mm of rain over about 36 wet days across the season. It is the 2nd-warmest season and the wettest season of the year.

Over the season highs ease from about 24°C in early September to 12°C by late November. The sky is clear or mostly clear about 39% of the time across fall, and the air most often feels dry.

Fall is Piran's 2nd-best season to visit on our travel score. For the whole year in context, see Piran's year-round climate.

Avg daytime high
18°C
2nd-warmest season
Avg overnight low
15°C
Rainfall
454 mm
36 wet days
Avg wind
15 km/h
Travel score
5.4
2nd-best season
Months
Sep · Oct · Nov

Temperature in Piran in Fall

Average highAverage lowShaded bands: 10–90% of days

Over the season highs ease from about 24°C in early September to 12°C by late November.

A typical fall day in Piran reaches about 18°C and drops to 15°C overnight. The warmest of the three months is September, the coolest November.

10°15°20°25°30°SepOctNov

Piran weather by month

How the three fall months (September, October and November) compare with the rest of the year — the season's months are highlighted.

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 Fall

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 39% of the time across fall.

0%25%50%75%100%SepOctNov

Chance of precipitation in Fall

Any precipitation

Piran gets around 454 mm of rain over 36 wet days across fall. The line is the day-by-day chance of measurable precipitation.

0%20%40%60%SepOctNov

Humidity in Fall

DryComfortableHumidMuggyOppressiveMiserable

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

0%25%50%75%100%SepOctNov

Wind in Fall

Winds average 15 km/h across fall.

05101520SepOctNov

Sunrise & sunset in Fall

DaylightNight

Daylight runs from about 13 h 06 min in early September to 8 h 48 min by late November. The lit band spans sunrise to sunset each day.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMSepOctNov

Solar energy in Fall

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day across fall, about 2.8 kWh/m².

024SepOctNov
Planning a trip in fall

Is fall a good time to visit Piran?

Our two travel scores rate fall for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.

5.4
Sightseeing
2nd-best month of the year
2.3
Beach & pool
2nd-best month of the year

fall is a reasonable time to visit Piran for sightseeing.

What to pack for Piran in Fall

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

In fall, Piran sees daytime highs around 18°C and nights near 15°C. Pack rain gear. Worth having: light clothes and a warm layer. About 36 days see rain.

rain gearlight clothesa warm layer

Sea temperature near Piran in Fall

The nearest coast averages about 19°C across fall — 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 Fall

LowModerateHighVery highExtreme

Clear-sky midday UV across fall averages around 3 — 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.

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 Fall

GoodModeratePoorUnhealthyVery unhealthy

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