Trieste in Fall

In fall (September, October and November), Trieste sees average daytime highs around 16°C and overnight lows near 11°C, with 548 mm of precipitation over about 38 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 23°C in early September to 9°C by late November. The sky is clear or mostly clear about 34% of the time across fall, and the air most often feels dry.

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

Avg daytime high
16°C
2nd-warmest season
Avg overnight low
11°C
Precipitation
548 mm
38 wet days
Avg wind
10 km/h
Travel score
4.6
2nd-best season
Months
Sep · Oct · Nov

Temperature in Trieste in Fall

Average highAverage lowShaded bands: 10–90% of days

Over the season highs ease from about 23°C in early September to 9°C by late November.

A typical fall day in Trieste reaches about 16°C and drops to 11°C overnight. The warmest of the three months is September, the coolest November.

10°20°30°SepOctNov

How fall really feels in Trieste

Once humidity and wind are folded in, fall brings about 0 days that feel above 32°C and 0 that feel at or below 0°C.

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

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

Trieste 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 / 909.52.78.90.5
Feb / 978.62.910.11.1
Mar11° / 1019.71.611.62.7
Apr15° / 11012.10.513.34.2
May19° / 13°12213014.75.8
Jun23° / 17°11112.2015.46.7
Jul26° / 19°8710.7015.17.0
Aug26° / 19°11110.3013.97.0
Sep21° / 15°17011.4012.36.4
Oct16° / 11°184130.110.74.8
Nov11° / 19513.21.19.32.5
Dec / 12910.12.18.60.9

Cloud cover in Fall

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 34% of the time across fall.

0%25%50%75%100%SepOctNov

Chance of precipitation in Fall

Any precipitationSnow

Trieste gets around 548 mm of rain and snow over 38 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 10 km/h across fall.

051015SepOctNov

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 2.6 kWh/m².

024SepOctNov
Planning a trip in fall

Is fall a good time to visit Trieste?

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.

4.6
Sightseeing
2nd-best month of the year
1.6
Beach & pool
2nd-best month of the year

fall is a reasonable time to visit Trieste for sightseeing.

What to pack for Trieste in Fall

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

In fall, Trieste sees daytime highs around 16°C and nights near 11°C. Pack a warm layer. Worth having: rain gear. About 38 days see rain.

a warm layerrain gear

Sea temperature near Trieste 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 Trieste 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 Trieste 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 Trieste 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 Trieste is worst in January — around 16 µg/m³ PM2.5 (moderate), about 1.8× the cleanest month (September, 9 µg/m³).

Seasonal pattern from CAMS reanalysis, scaled to Trieste's WHO annual average of 12 µg/m³.

01020JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateJan 1816 µg/m³Sep 149 µg/m³
PM2.5 (µg/m³)Level
Jan16Moderate
Feb14Moderate
Mar14Moderate
Apr13Moderate
May11Good
Jun12Good
Jul12Good
Aug10Good
Sep9Good
Oct10Good
Nov10Good
Dec13Moderate
Location & terrain

Where is Trieste?

Trieste sits at 45.6°N, 13.8°E, 2 m above sea level, in Italy. The nearest listed city is Koper, 12 km away.

Topography around Trieste

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

Within 3 km, the terrain around Trieste has significant variations in elevation — a maximum elevation change of 451 m around an average of 72 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 779 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,524 m.

The land around Trieste is covered by artificial surfaces (41%), trees (31%) and water (27%) within 3 km, trees (50%) and water (32%) within 16 km, and trees (52%) and water (23%) within 80 km.

3 km
451 m
16 km
779 m
80 km
2,524 m
treesshrubsgrasslandcroplandartificial surfaceswater
Fall weather nearby: Koper 12 km · Divača 16 km · Piran 21 km · Monfalcone 26 km · Gorizia 35 km · Nova Gorica 36 km · Postojna 37 km · Udine 63 km

Italy travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / F / L
230 V · 50 Hz
Prices
≈ 69% of US
price level, 2025
GDP per capita
$43,309
2025
Happiness
6.6 / 10
World Happiness, 2025
Safe drinking water
97%
of population, 2024
Homicide rate
0.6
per 100k, 2023
Road deaths
5.3
per 100k/yr, 2019
Income group
High
World Bank
English
Moderate
EF EPI 513
Religion
Christian 81%unaffiliated 13%Muslim 5%other 1%

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 Trieste (45.6495°, 13.7768°, elevation 2 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.