Climate averages 1991–2020
Terni weather
in December.
A cool, wet month: the 11th warmest and the 11th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
December is a cool month in Terni: daytime highs average 11.1°C and nights cool to about 3.2°C. By daytime temperature it is the 11th warmest of the 12 months.
Expect about 107 mm of rain on roughly 11 days, which makes December a wet month (the 11th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 9 h 07 min on an average December day.
The nearest other city in this atlas is Guidonia Montecelio (64 km away). In December its highs average 11.9°C, 0.7°C warmer than Terni, with 104 mm of rain.
Among the 79 cities listed in Italy, Terni ranks joint 36th of 79 for the warmest December highs and 60th of 79 for the driest December (rainfall, lowest first). The mean December high of those 79 cities is 10.5°C; Terni is 0.7°C warmer than that mean.
From December to January, average highs fall by 0.6°C to 10.5°C, and monthly rainfall falls from 107 mm to 71 mm.
The annual picture
December in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Terni climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 10.5°C2.2°C | 2.2°C | 71 | 9.5 | 9.49 h |
| February | 11.6°C2.2°C | 2.2°C | 82 | 10.0 | 10.511 h |
| March | 15.0°C4.5°C | 4.5°C | 92 | 10.8 | 11.912 h |
| April | 18.4°C7.4°C | 7.4°C | 98 | 13.0 | 13.313 h |
| May | 22.9°C11.4°C | 11.4°C | 83 | 11.3 | 14.615 h |
| June | 27.8°C15.5°C | 15.5°C | 53 | 8.7 | 15.215 h |
| July | 31.4°C18.5°C | 18.5°C | 30 | 5.7 | 15.015 h |
| August | 31.6°C19.0°C | 19.0°C | 33 | 6.1 | 13.914 h |
| September | 25.6°C15.0°C | 15.0°C | 81 | 9.4 | 12.513 h |
| October | 20.7°C11.5°C | 11.5°C | 105 | 10.5 | 11.111 h |
| November | 15.3°C7.2°C | 7.2°C | 129 | 12.4 | 9.810 h |
| December, selected | 11.1°C3.2°C | 3.2°C | 107 | 10.7 | 9.19 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
December in nearby cities
- Guidonia Montecelio in DecemberItaly · 64 kmHigh 11.9°C · Low 3.3°C · 104 mm rain
- Perugia in DecemberItaly · 64 kmHigh 8.0°C · Low 0.8°C · 83 mm rain
- Rome in DecemberItaly · 75 kmHigh 12.3°C · Low 5.1°C · 94 mm rain
- Acilia-Castel Fusano-Ostia Antica in DecemberItaly · 93 kmHigh 12.9°C · Low 7.9°C · 115 mm rain
- Fiumicino in DecemberItaly · 94 kmHigh 13.0°C · Low 8.3°C · 115 mm rain
- Aprilia in DecemberItaly · 108 kmHigh 12.5°C · Low 6.4°C · 121 mm rain
- Arezzo in DecemberItaly · 118 kmHigh 9.3°C · Low 2.7°C · 99 mm rain
- Latina in DecemberItaly · 124 kmHigh 12.7°C · Low 5.9°C · 115 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Terni) is explained once on the Terni year overview and on the Sources, method and limits page.