Trieste weather in December

In December, Trieste sees average daytime highs of 7°C and overnight lows near 3°C, with 129 mm of precipitation across 10.1 wet days and about 8.6 hours of daylight. It is the 11th-warmest and 4th-wettest month of the year here.

Highs ease over the month, from about 8°C in the first days to 6°C by the end. The sky is clear or mostly clear about 32% of the time in December, and the air most often feels dry.

Daylight stretches from about 8 h 48 min at the start of December to 8 h 30 min by month's end. Set against the rest of the year, December is Trieste's 10th-clearest and 1st-windiest month. For the whole year in context, see Trieste's year-round climate.

Daytime high
11th warmest
Overnight low
3rd coldest
Precipitation
129 mm
10.1 wet days
Daylight
8 h 30 min
7:46 AM – 4:16 PM
Cloud cover
61%
10th clearest
Wind
11 km/h
1st windiest
Solar energy
1.14 kWh/m²
Travel score
0.9
out of 10
Air quality
Moderate
PM2.5 12 µg/m³ · 2019

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 8°C in the first days to 6°C by the end.

A typical December day in Trieste reaches about 7°C in the afternoon and slips back to 3°C overnight — a 4°C spread between the day's warmth and the night's chill. On most days the high lands between 3°C and 11°C. Set against its neighbours, December runs about 4°C cooler than November and about 1°C warmer than January.

-5°10°15°151015202531
Avg high (°C)Avg low (°C)
185
284
384
484
584
684
784
884
984
1073
1173
1273
1373
1473
1573
1673
1773
1873
1973
2073
2173
2272
2372
2462
2562
2662
2762
2862
2962
3062
3162

How December really feels in Trieste

Once humidity and wind are folded in, December averages 0 days that feel above 32°C and 16 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
16
wind chill below the day's low

The story in December is cold — wind chill drags the overnight "feels like" below the raw low.

Trieste weather by month

How December compares with the rest of the year at a glance. December is the 11th-warmest and 4th-wettest month here — the current month is highlighted below.

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 December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 32% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 12% of December, with mostly cloudy or overcast conditions the remaining 56%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14060
24159
34258
44357
54357
64357
74456
84357
94357
104456
114456
124456
134357
144456
154456
164357
174357
184357
194357
204357
214357
224357
234555
244555
254555
264456
274555
284555
294555
304456
314555

Chance of precipitation in December

Any precipitationSnow

Trieste gets around 129 mm of rain and snow over 10.1 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 33% and peaks near 36% on the wettest days, and about 2 days bring snow.

0%10%20%30%40%50%151015202531
Rain chance (%)Snow chance (%)
1367
2367
3357
4357
5347
6346
7336
8336
9336
10336
11336
12326
13326
14326
15326
16326
17326
18326
19327
20327
21337
22337
23337
24338
25338
26328
27328
28338
29338
30338
31338

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, December lands in the dry band about 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)
1100
2100
3100
4100
5100
6100
7100
8100
9100
10100
11100
12100
13100
14100
15100
16100
17100
18100
19100
20100
21100
22100
23100
24100
25100
26100
27100
28100
29100
30100
31100

Wind in December

Winds average 11 km/h in December, the windiest month of the year.

Across December, daily wind ranges from about 10 km/h on the calmest days to 11 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
111calm
211calm
311calm
411calm
511calm
611calm
711calm
811calm
911calm
1011calm
1111calm
1211calm
1311calm
1411calm
1511calm
1611calm
1711calm
1811calm
1911calm
2011calm
2111calm
2211calm
2311calm
2411calm
2511calm
2611calm
2710calm
2810calm
2910calm
3010calm
3110calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 8 h 48 min at the start of December to 8 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 18 minutes over December. Sunrise moves from 7:32 AM to 7:52 AM, and sunset from 4:17 PM to 4:24 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
18.87:324:17
28.77:334:17
38.77:344:17
48.77:354:16
58.77:364:16
68.67:374:16
78.67:384:16
88.67:394:16
98.67:404:16
108.67:414:16
118.67:424:16
128.67:434:16
138.57:434:16
148.57:444:16
158.57:454:16
168.57:464:16
178.57:464:17
188.57:474:17
198.57:484:17
208.57:484:18
218.57:494:18
228.57:494:19
238.57:504:19
248.57:504:20
258.57:504:20
268.57:514:21
278.57:514:21
288.57:514:22
298.57:524:23
308.57:524:23
318.57:524:24

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 1.14 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 1.14 kWh/m² to a high of 6.28 kWh/m² in July across the year — December's 1.14 kWh/m² sits near the bottom.

00.511.52151015202531
Solar energy (kWh/m²)Level
11.2Dim
21.2Dim
31.2Dim
41.2Dim
51.2Dim
61.2Dim
71.2Dim
81.2Dim
91.2Dim
101.1Dim
111.1Dim
121.1Dim
131.1Dim
141.1Dim
151.1Dim
161.1Dim
171.1Dim
181.1Dim
191.1Dim
201.1Dim
211.1Dim
221.1Dim
231.1Dim
241.1Dim
251.1Dim
261.1Dim
271.1Dim
281.1Dim
291.1Dim
301.1Dim
311.1Dim
Planning a trip in December

Is December a good time to visit Trieste?

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

0.9
Sightseeing
11th-best month of the year
0.0
Beach & pool
9th-best month of the year

December is a weaker month for outdoor sightseeing in Trieste.

What to pack for Trieste in December

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

In December, Trieste sees daytime highs around 7°C and nights near 3°C. Pack a warm layer. Worth having: a heavy coat and rain gear. About 10 days see rain.

a warm layera heavy coatrain gear

Sea temperature near Trieste in December

The nearest coast averages about 13°C in December — 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 December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 1. 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 December

GoodModeratePoorUnhealthyVery unhealthy

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