Isernia in Fall
In fall (September, October and November), Isernia sees average daytime highs around 18°C and overnight lows near 9°C, with 339 mm of precipitation over about 33 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 11°C by late November. The sky is clear or mostly clear about 35% of the time across fall, and the air most often feels dry.
Fall is Isernia's 2nd-best season to visit on our travel score. For the whole year in context, see Isernia's year-round climate.
- Avg daytime high
- 18°C
- 2nd-warmest season
- Avg overnight low
- 9°C
- Precipitation
- 339 mm
- 33 wet days
- Avg wind
- 5 km/h
- Travel score
- 5.3
- 2nd-best season
- Months
- Sep · Oct · Nov
Temperature in Isernia in Fall
Over the season highs ease from about 24°C in early September to 11°C by late November.
A typical fall day in Isernia reaches about 18°C and drops to 9°C overnight. The warmest of the three months is September, the coolest November.
How fall really feels in Isernia
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.
fall sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.
Isernia 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.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 8° / 0° | 88 | 10.6 | 2.4 | 9.3 | 1.3 |
| Feb | 9° / 1° | 92 | 11.1 | 2.8 | 10.3 | 1.6 |
| Mar | 12° / 3° | 106 | 12.9 | 2.2 | 11.7 | 2.9 |
| Apr | 15° / 6° | 108 | 14.2 | 0.3 | 13.1 | 4.1 |
| May | 19° / 10° | 89 | 12.9 | 0 | 14.3 | 5.8 |
| Jun | 24° / 14° | 62 | 10.2 | 0 | 15 | 7.1 |
| Jul | 26° / 16° | 43 | 8.3 | 0 | 14.7 | 7.4 |
| Aug | 27° / 16° | 36 | 8.3 | 0 | 13.7 | 7.3 |
| Sep | 22° / 13° | 79 | 10.4 | 0 | 12.3 | 6.8 |
| Oct | 18° / 9° | 111 | 10.4 | 0.1 | 10.9 | 5.8 |
| Nov | 13° / 5° | 150 | 12.5 | 0.8 | 9.7 | 3.4 |
| Dec | 9° / 2° | 121 | 12.4 | 2.4 | 9 | 1.7 |
Cloud cover in Fall
The sky is clear or mostly clear about 35% of the time across fall.
Chance of precipitation in Fall
Isernia gets around 339 mm of rain and snow over 33 wet days across fall. The line is the day-by-day chance of measurable precipitation.
Humidity in Fall
Most of fall feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Fall
Winds average 5 km/h across fall.
Sunrise & sunset in Fall
Daylight runs from about 13 hours in early September to 9 h 12 min by late November. The lit band spans sunrise to sunset each day.
Solar energy in Fall
Average shortwave solar energy reaching the ground each day across fall, about 3.2 kWh/m².
Is fall a good time to visit Isernia?
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.
fall is a reasonable time to visit Isernia for sightseeing.
What to pack for Isernia in Fall
From fall's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In fall, Isernia sees daytime highs around 18°C and nights near 9°C. Worth packing: light clothes, a warm layer and rain gear. About 33 days see rain.
Sea temperature near Isernia in Fall
The nearest coast averages about 22°C across fall — 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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 15 | 14 | 14 | 16 | 19 | 22 | 25 | 26 | 24 | 22 | 19 | 17 |
| Comfort | Bracing | Bracing | Bracing | Cool | Cool | Refreshing | Warm | Warm | Warm | Refreshing | Cool | Cool |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 15 | Bracing |
| Feb | 14 | Bracing |
| Mar | 14 | Bracing |
| Apr | 16 | Cool |
| May | 19 | Cool |
| Jun | 22 | Refreshing |
| Jul | 25 | Warm |
| Aug | 26 | Warm |
| Sep | 24 | Warm |
| Oct | 22 | Refreshing |
| Nov | 19 | Cool |
| Dec | 17 | Cool |
UV index in Isernia in Fall
Clear-sky midday UV across fall averages around 4 — enough to warrant sun protection. 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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 2 | 3 | 5 | 5 | 7 | 9 | 10 | 9 | 6 | 4 | 2 | 1 |
| Level | Low | Moderate | High | Moderate | Very high | Very high | Extreme | Very high | High | Moderate | Moderate | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 2 | Low |
| Feb | 3 | Moderate |
| Mar | 5 | High |
| Apr | 5 | Moderate |
| May | 7 | Very high |
| Jun | 9 | Very high |
| Jul | 10 | Extreme |
| Aug | 9 | Very high |
| Sep | 6 | High |
| Oct | 4 | Moderate |
| Nov | 2 | Moderate |
| Dec | 1 | Low |
Air quality in Isernia in Fall
Average fine-particle pollution (PM2.5) through the year — so you can see where fall 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).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 19 | 20 | 21 | 22 | 18 | 16 | 16 | 16 | 14 | 16 | 16 | 17 |
| Level | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 19 | Moderate |
| Feb | 20 | Moderate |
| Mar | 21 | Moderate |
| Apr | 22 | Moderate |
| May | 18 | Moderate |
| Jun | 16 | Moderate |
| Jul | 16 | Moderate |
| Aug | 16 | Moderate |
| Sep | 14 | Moderate |
| Oct | 16 | Moderate |
| Nov | 16 | Moderate |
| Dec | 17 | Moderate |
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.
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
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.