Climate averages 1991–2020
Viseu 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 Viseu: daytime highs average 11.1°C and nights cool to about 4.1°C. By daytime temperature it is the 11th warmest of the 12 months.
Expect about 160 mm of rain on roughly 12 days, which makes December a wet month (the 11th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 9 h 19 min on an average December day.
The nearest other city in this atlas is Aveiro (62 km away). In December its highs average 14.3°C, 3.2°C warmer than Viseu, with 141 mm of rain.
Among the 12 cities listed in Portugal, Viseu ranks 12th of 12 for the warmest December highs and 10th of 12 for the driest December (rainfall, lowest first). The mean December high of those 12 cities is 14.4°C; Viseu is 3.4°C cooler than that mean.
From December to January, average highs fall by 0.6°C to 10.5°C, and monthly rainfall falls from 160 mm to 152 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
Viseu climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 10.5°C3.1°C | 3.1°C | 152 | 11.6 | 9.610 h |
| February | 12.0°C3.4°C | 3.4°C | 102 | 9.3 | 10.611 h |
| March | 15.0°C5.4°C | 5.4°C | 115 | 10.6 | 11.912 h |
| April | 16.6°C7.1°C | 7.1°C | 118 | 12.8 | 13.313 h |
| May | 20.0°C9.9°C | 9.9°C | 98 | 11.6 | 14.414 h |
| June | 24.2°C13.1°C | 13.1°C | 40 | 6.2 | 15.015 h |
| July | 27.6°C15.4°C | 15.4°C | 19 | 3.6 | 14.815 h |
| August | 27.9°C15.8°C | 15.8°C | 26 | 4.6 | 13.814 h |
| September | 24.3°C13.7°C | 13.7°C | 66 | 7.1 | 12.513 h |
| October | 18.9°C10.5°C | 10.5°C | 168 | 12.2 | 11.211 h |
| November | 13.6°C6.4°C | 6.4°C | 150 | 12.7 | 10.010 h |
| December, selected | 11.1°C4.1°C | 4.1°C | 160 | 11.6 | 9.39 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
- Aveiro in DecemberPortugal · 62 kmHigh 14.3°C · Low 7.6°C · 141 mm rain
- Coimbra in DecemberPortugal · 67 kmHigh 14.3°C · Low 6.0°C · 111 mm rain
- Porto in DecemberPortugal · 80 kmHigh 13.5°C · Low 7.4°C · 167 mm rain
- Braga in DecemberPortugal · 108 kmHigh 12.5°C · Low 4.8°C · 205 mm rain
- Leiria in DecemberPortugal · 127 kmHigh 15.0°C · Low 8.2°C · 91 mm rain
- Cáceres, Spain in DecemberSpain · 186 kmHigh 12.1°C · Low 4.7°C · 67 mm rain
- Ourense in DecemberSpain · 186 kmHigh 12.2°C · Low 4.6°C · 114 mm rain
- Vigo in DecemberSpain · 187 kmHigh 13.1°C · Low 7.4°C · 224 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 Viseu) is explained once on the Viseu year overview and on the Sources, method and limits page.