Isernia, Italy Climate
The warmest month is August, with an average high of 32°C; the coldest is February, with an average low of 2°C. A normal year brings 764 mm of precipitation.
Temperature through the year
The normal daily high and low. The line marks today.
- Normal low
- Normal high
- Reanalysis extreme high
- Reanalysis extreme low
Normals for Sep 25
- Normal high
- 24°C
- Normal low
- 13°C
- Reanalysis high
- 30°Cin 1999
- Reanalysis low
- 9°Cin 2008
- Chance of a wet day
- 33%
- Daylight
- 12 h 02 min
Month by month
Averages for 1991-2020. Wet days have at least 1 mm of precipitation in the reanalysis. Each month links to its own page.
| Month | Avg high | Avg low | Warmest | Coldest | Precipitation | Wet days |
|---|---|---|---|---|---|---|
| January | 10°C | 2°C | 17°C (2007) | -7°C (2017) | 78 mm | 9.3 |
| February | 10°C | 2°C | 20°C (1998) | -7°C (2003) | 65 mm | 11.3 |
| March | 13°C | 4°C | 23°C (2002) | -6°C (2005) | 65 mm | 9.3 |
| April | 17°C | 7°C | 27°C (2019) | -4°C (2003) | 60 mm | 9.0 |
| May | 22°C | 11°C | 33°C (2009) | 2°C (1991) | 47 mm | 9.3 |
| June | 28°C | 15°C | 37°C (2003) | 7°C (2005) | 36 mm | 6.0 |
| July | 32°C | 18°C | 41°C (2005) | 10°C (1991) | 25 mm | 6.2 |
| August | 32°C | 19°C | 42°C (2017) | 9°C (1995) | 25 mm | 6.2 |
| September | 26°C | 15°C | 37°C (2008) | 6°C (2002) | 69 mm | 9.0 |
| October | 21°C | 11°C | 30°C (1997) | 1°C (2012) | 87 mm | 9.3 |
| November | 15°C | 7°C | 24°C (2004) | -3°C (1995) | 117 mm | 12.0 |
| December | 11°C | 3°C | 18°C (1994) | -6°C (2010) | 90 mm | 12.4 |
| Year | 20°C | 9°C | 764 mm | 109 |
Precipitation
Rain and melted snow together. The chance of a wet day is the share of days with at least 1 mm of precipitation in the reanalysis.
764 mm in a normal year, most in November.
Chance of a wet day
- Chance of a wet day
Humidity and comfort
NASA POWER reanalysis, 1991-2020, for the grid cell around Isernia.
The muggiest month is August, when 1 percent of days are muggy or worse, with a mean dew point of 18°C or more.
| Month | Dew point | Humidity | Dry | Comfortable | Humid | Muggy | Oppressive | Miserable |
|---|---|---|---|---|---|---|---|---|
| January | 3°C | 85% | 100% | 0% | 0% | 0% | 0% | 0% |
| February | 2°C | 82% | 100% | 0% | 0% | 0% | 0% | 0% |
| March | 5°C | 79% | 100% | 0% | 0% | 0% | 0% | 0% |
| April | 7°C | 75% | 100% | 0% | 0% | 0% | 0% | 0% |
| May | 10°C | 69% | 87% | 12% | 0% | 0% | 0% | 0% |
| June | 12°C | 60% | 58% | 36% | 6% | 0% | 0% | 0% |
| July | 13°C | 52% | 49% | 39% | 12% | 0% | 0% | 0% |
| August | 13°C | 52% | 43% | 44% | 12% | 1% | 0% | 0% |
| September | 12°C | 66% | 58% | 29% | 12% | 1% | 0% | 0% |
| October | 10°C | 76% | 75% | 19% | 5% | 0% | 0% | 0% |
| November | 7°C | 84% | 94% | 6% | 0% | 0% | 0% | 0% |
| December | 4°C | 85% | 100% | 0% | 0% | 0% | 0% | 0% |
Comfort is judged by the day's mean dew point: dry below 13°C, comfortable to 16°C, humid to 18°C, muggy to 21°C, oppressive to 24°C, miserable above.
Clouds
Average share of the sky covered, from satellite (CERES and GEWEX SRB) by way of NASA POWER, 1991-2020.
The clearest month is July, with the sky 34 percent covered on average; the cloudiest is January, at 68 percent.
Wind
The mean wind speed over the whole day, from the MERRA-2 reanalysis by way of NASA POWER. Gusts run well above it.
The windiest month is March, averaging 11.2 km/h at 10 meters (33 feet) above the ground.
Daylight and sunshine
The longest day is Jun 16, with 15 h 12 min of daylight; the shortest is Dec 19, with 9 h 09 min.
- Day length
Solar energy
Average daily sunshine reaching the ground on a flat surface, in kilowatt-hours per square meter, clouds included.
Month pages
The weather in Isernia in each month, day by day.
What this means
A normal is the average of the thirty years 1991 to 2020, the period the World Meteorological Organization and NOAA use for comparison. It is an average, not a forecast: most days depart from it, and some by a long way.
Where no station record is within reach, the extremes shown are the highest and lowest the reanalysis produced for the date in 1991-2020, not measured records.
Cloud, humidity, wind and sunshine come from a reanalysis: a weather model run over the past with every observation fed in, averaged over a grid cell about 50 km across. It is consistent everywhere on Earth; it smooths local detail such as a lake shore or a valley.
More for this place
Nearby
Sources
Cloud, humidity, wind and sunshine, and temperature and precipitation: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.