Isernia weather in December

In December, Isernia sees average daytime highs of 9°C and overnight lows near 2°C, with 121 mm of precipitation across 12.4 wet days and about 9 hours of daylight. It is the 10th-warmest and 2nd-wettest month of the year here.

Highs ease over the month, from about 10°C in the first days to 8°C by the end. The sky is clear or mostly clear about 30% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 12 min at the start of December to 9 hours by month's end. Set against the rest of the year, December is Isernia's 8th-clearest and 3rd-windiest month. For the whole year in context, see Isernia's year-round climate.

Daytime high
10th warmest
Overnight low
3rd coldest
Precipitation
121 mm
12.4 wet days
Daylight
9 hours
7:29 AM – 4:29 PM
Cloud cover
60%
8th clearest
Wind
6 km/h
3rd windiest
Solar energy
1.66 kWh/m²
Travel score
1.7
out of 10
Air quality
Excellent
PM10 11.9 µg/m³ · 2018

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 10°C in the first days to 8°C by the end.

A typical December day in Isernia reaches about 9°C in the afternoon and slips back to 2°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 5°C and 12°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)
1103
2103
3103
4103
5103
6103
7102
8102
992
1092
1192
1292
1392
1492
1591
1691
1791
1891
1991
2081
2181
2281
2381
2481
2581
2681
2781
2881
2981
3081
3181

How December really feels in Isernia

Once humidity and wind are folded in, December averages 0 days that feel above 32°C and 19 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
19
wind chill below the day's low

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

Isernia weather by month

How December compares with the rest of the year at a glance. December is the 10th-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 8810.62.49.31.3
Feb / 9211.12.810.31.6
Mar12° / 10612.92.211.72.9
Apr15° / 10814.20.313.14.1
May19° / 10°8912.9014.35.8
Jun24° / 14°6210.20157.1
Jul26° / 16°438.3014.77.4
Aug27° / 16°368.3013.77.3
Sep22° / 13°7910.4012.36.8
Oct18° / 11110.40.110.95.8
Nov13° / 15012.50.89.73.4
Dec / 12112.42.491.7

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 30% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 15% of December, with mostly cloudy or overcast conditions the remaining 55%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14258
24258
34357
44357
54357
64456
74456
84456
94456
104555
114555
124555
134555
144654
154654
164654
174654
184753
194654
204654
214753
224753
234654
244654
254753
264753
274654
284654
294753
304753
314753

Chance of precipitation in December

Any precipitationSnow

Isernia gets around 121 mm of rain and snow over 12.4 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 40% and peaks near 41% on the wettest days, and about 2 days bring snow.

0%10%20%30%40%50%151015202531
Rain chance (%)Snow chance (%)
1414
2414
3414
4414
5414
6415
7415
8405
9406
10406
11407
12397
13397
14398
15398
16398
17398
18398
19399
20399
21399
22399
23409
244010
254010
26409
27409
28409
29399
30399
31398

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 6 km/h in December.

Across December, daily wind ranges from about 6 km/h on the calmest days to 6 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm
316calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 h 12 min at the start of December to 9 hours by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 12 minutes over December. Sunrise moves from 7:17 AM to 7:35 AM, and sunset from 4:29 PM to 4:37 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.27:174:29
29.27:184:29
39.27:194:29
49.17:194:28
59.17:204:28
69.17:214:28
79.17:224:28
89.17:234:28
99.17:244:28
109.17:254:28
119.07:264:28
129.07:264:28
139.07:274:29
149.07:284:29
159.07:294:29
169.07:294:29
179.07:304:30
189.07:304:30
199.07:314:30
209.07:324:31
219.07:324:31
229.07:334:31
239.07:334:32
249.07:334:32
259.07:344:33
269.07:344:34
279.07:354:34
289.07:354:35
299.07:354:36
309.07:354:36
319.07:354:37

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 1.66 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 1.66 kWh/m² to a high of 6.8 kWh/m² in July across the year — December's 1.66 kWh/m² sits near the bottom.

00.511.522.5151015202531
Solar energy (kWh/m²)Level
11.7Dim
21.7Dim
31.7Dim
41.7Dim
51.7Dim
61.7Dim
71.7Dim
81.7Dim
91.7Dim
101.7Dim
111.7Dim
121.7Dim
131.7Dim
141.7Dim
151.7Dim
161.7Dim
171.7Dim
181.7Dim
191.7Dim
201.7Dim
211.7Dim
221.7Dim
231.7Dim
241.7Dim
251.7Dim
261.7Dim
271.7Dim
281.7Dim
291.7Dim
301.7Dim
311.7Dim
Planning a trip in December

Is December a good time to visit Isernia?

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

1.7
Sightseeing
10th-best month of the year
0.0
Beach & pool
9th-best month of the year

December is a weaker month for outdoor sightseeing in Isernia.

What to pack for Isernia in December

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

In December, Isernia sees daytime highs around 9°C and nights near 2°C. Pack a warm layer. Worth having: rain gear. About 12 days see rain.

a warm layerrain gear

Sea temperature near Isernia in December

The nearest coast averages about 17°C in December — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 60 km away) is warmest in August at about 26°C and coldest in February near 14°C.

It's comfortable for a long swim from May 27 to Nov 5 — about 5.4 months when the water holds above 20°C.

15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan15Bracing
Feb14Bracing
Mar14Bracing
Apr16Cool
May19Cool
Jun22Refreshing
Jul25Warm
Aug26Warm
Sep24Warm
Oct22Refreshing
Nov19Cool
Dec17Cool

UV index in Isernia 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 Isernia peaks around July 15 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJul 15UV 10Dec 21UV 1
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5High
Apr5Moderate
May7Very high
Jun9Very high
Jul10Extreme
Aug9Very high
Sep6High
Oct4Moderate
Nov2Moderate
Dec1Low

Air quality in Isernia 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 Isernia is worst in April — around 22 µg/m³ PM2.5 (moderate), and holds fairly steady the rest of the year.

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateApr 1021 µg/m³Sep 1714 µg/m³
PM2.5 (µg/m³)Level
Jan19Moderate
Feb20Moderate
Mar21Moderate
Apr22Moderate
May18Moderate
Jun16Moderate
Jul16Moderate
Aug16Moderate
Sep14Moderate
Oct16Moderate
Nov16Moderate
Dec17Moderate
Location & terrain

Where is Isernia?

Isernia sits at 41.6°N, 14.2°E, 423 m above sea level, in Italy. The nearest listed city is Cassino, 36 km away.

Topography around Isernia

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

Within 3 km, the terrain around Isernia has significant variations in elevation — a maximum elevation change of 398 m around an average of 468 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,340 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,771 m.

The land around Isernia is covered by trees (63%) within 3 km, trees (72%) and grassland (22%) within 16 km, and trees (51%) and cropland (21%) within 80 km.

3 km
398 m
16 km
1,340 m
80 km
2,771 m
treesshrubsgrasslandcroplandartificial surfaceswater
December weather nearby: Cassino 36 km · Campobasso 36 km · Sora 53 km · Capua 55 km · Minturno 55 km · Sulmona 57 km · Santa Maria Capua Vetere 57 km · Caserta 59 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 Isernia (41.596°, 14.234°, elevation 423 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).