Isernia climate — normals and trends
Isernia has a temperate oceanic climate, averaging 11.7 °C annually with 1,099 mm of rain per year.
Climate normals · ERA5
IserniaMolise
- coords
- 41.60°, 14.23°
- period
- 1940–2025 · 86 yrs
The normals for this period
The average of every indicator across the whole window: temperature, water, sky, wind and notable days.
Mean daily temperature
11.7°C
Average daily high
16.3°C
Average daily low
7.4°C
Annual rainfall
1,099mm
Sunshine / day
9.8h
Mean relative humidity
78%
Average peak wind
9.4km/h
Seasonal range
17.6°C
Frost days (< 0 °C)
53 d/yr
Hot days (≥ 30 °C)
7 d/yr
Rainy days (≥ 1 mm)
139 d/yr
Annual snowfall
40.6 cm
Average feels-like high
15.7 °C
Average feels-like low
5.9 °C
Average peak gust
34.8 km/h
Tropical nights (≥ 20 °C)
2 d/yr
Solar radiation
15.2 MJ/m²
Has the climate changed?
What the yearly averages say about warming here, and whether the slope is statistically solid.
+2.0 °C
since 1940
+0.2 °C per decade · r² = 0.51 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
Climate month by month
How an average year unfolds: when it rains, when it turns hot, when the sun is out.
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
The most extreme days ever measured here, then the year-by-year detail.
Hottest day
35.6 °C
19 August 1946
Coldest day
-18.9 °C
11 January 1985
Wettest day
80 mm
15 November 1979
Windiest day
35.8 km/h
30 December 1974
Strongest gust
131.4 km/h
30 December 1974
Hottest feels-like
39.3 °C
18 July 2023
Coldest feels-like
-24.0 °C
28 December 1940
Snowiest day
36.9 cm
3 February 2012
Sunniest day
14.1 h
6 July 2025
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and compare it with the normal: warmer, drier, more extreme?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 9.2 °C | +2.0 °C | 99 mm | -2 mm |
| Feb | 10.5 °C | +2.0 °C | 67 mm | -35 mm |
| Mar | 13.4 °C | +2.2 °C | 156 mm | +55 mm |
| Apr | 16.7 °C | +2.2 °C | 123 mm | +21 mm |
| May | 19.4 °C | +0.6 °C | 76 mm | -12 mm |
| Jun | 28.6 °C | +5.8 °C | 20 mm | -45 mm |
| Jul | 28.5 °C | +2.6 °C | 28 mm | -14 mm |
| Aug | 28.2 °C | +2.0 °C | 68 mm | +26 mm |
| Sep | 24.2 °C | +1.8 °C | 98 mm | +23 mm |
| Oct | 17.5 °C | -0.1 °C | 80 mm | -29 mm |
| Nov | 13.4 °C | +1.1 °C | 138 mm | -11 mm |
| Dec | 11.1 °C | +2.6 °C | 42 mm | -82 mm |
The year's extremes
What was the weather like that day?
The weather actually measured on a given date, anywhere in the covered window.
Climate at a glance
What these normals say about the place, in a few sentences, and the notions needed to read them.
Isernia (Italy) has a temperate oceanic climate (Cfb) under the Köppen-Geiger classification. Its mean annual temperature is 11.7 °C and it receives 1,099 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is July (20.8 °C on average) and the coldest is January (3.2 °C). Rainfall peaks in November.
Isernia averages 53 frost days, 7 hot days (≥ 30 °C) and 139 rainy days per year.
Isernia has warmed by +2.0 °C between 1940 and 2025, or +0.23 °C per decade. This trend is statistically significant.
The number of frost days there went from about 71 to 35 per year over the period.
The hottest day of the period reached 35.6 °C (on 19 August 1946) and the coldest -18.9 °C (on 11 January 1985).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Compare Isernia with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Isernia
Other cities — Italy
Frequently asked questions
What is the climate of Isernia?
Isernia has a temperate oceanic climate (Köppen Cfb). Over 1940-2025, the average annual temperature is 11.7 °C and it receives 1,099 mm of precipitation per year.
What is the hottest day ever recorded in Isernia?
The hottest day measured in Isernia between 1940 and 2025 was 19 August 1946, reaching 35.6 °C.
What is the coldest day in Isernia?
The coldest day measured in Isernia between 1940 and 2025 was 11 January 1985, at -18.9 °C.
Does it snow in Isernia?
Yes. Isernia gets on average 40.6 cm of snow per year and has around 53 frost days.
Has the climate of Isernia warmed?
Yes: Isernia warmed by +2.0 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Isernia?
The wettest day measured in Isernia between 1940 and 2025 was 15 November 1979, with 80 mm of rain in 24 hours.
What was the windiest day in Isernia?
The windiest day measured in Isernia between 1940 and 2025 was 30 December 1974, with winds reaching 35.8 km/h.
What is the warmest month in Isernia?
The warmest month in Isernia is July (20.8 °C on average); the coldest is January (3.2 °C).
How much does it rain in Isernia?
Isernia receives on average 1,099 mm of precipitation per year, spread over about 139 rainy days.
Is it sunny in Isernia?
Isernia gets on average 9.8 hours of sunshine per day, roughly 3,577 hours per year over 1940-2025.
What is the biggest single-day snowfall in Isernia?
The heaviest 24-hour snowfall measured in Isernia between 1940 and 2025 was 3 February 2012, with 36.9 cm.
Are there tropical nights in Isernia?
Yes: Isernia has on average 2 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Isernia?
In Isernia, between 1940 and 2025, the highest apparent temperature reached 39.3 °C on 18 July 2023, and the lowest was -24.0 °C on 28 December 1940.
These forecasts and records come from our own weather API. Developer documentation →