Eiras weather in December

In December, Eiras sees average daytime highs of 14°C and overnight lows near 7°C, with 111 mm of rain across 10.9 wet days and about 9.2 hours of daylight. It is the 11th-warmest and 3rd-wettest month of the year here.

Day-to-day highs hold fairly steady near 14°C through the month. The sky is clear or mostly clear about 35% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 18 min at the start of December to 9 h 12 min by month's end. Set against the rest of the year, December is Eiras's 12th-clearest and 1st-windiest month. For the whole year in context, see Eiras's year-round climate.

Daytime high
14°
11th warmest
Overnight low
3rd coldest
Rainfall
111 mm
10.9 wet days
Daylight
9 h 06 min
7:55 AM – 5:04 PM
Cloud cover
57%
12th clearest
Wind
11 km/h
1st windiest
Solar energy
1.81 kWh/m²
Travel score
4.1
out of 10

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 14°C through the month.

A typical December day in Eiras reaches about 14°C in the afternoon and slips back to 7°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 11°C and 17°C. Set against its neighbours, December runs about 3°C cooler than November and on par with January.

10°15°20°151015202531
Avg high (°C)Avg low (°C)
1157
2157
3157
4157
5157
6157
7147
8147
9147
10147
11147
12147
13147
14147
15147
16147
17147
18147
19147
20147
21147
22147
23146
24146
25146
26146
27146
28146
29146
30146
31146

Eiras weather by month

How December compares with the rest of the year at a glance. December is the 11th-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan14° / 10810.89.53.9
Feb15° / 808.610.44.7
Mar18° / 859.611.75.9
Apr19° / 10°9210.7136.1
May22° / 12°739.214.26.9
Jun25° / 14°235.114.87.9
Jul27° / 16°92.214.68.2
Aug28° / 16°143.113.67.8
Sep25° / 15°49612.37.7
Oct21° / 12°11711.210.96.4
Nov17° / 11711.99.85.1
Dec14° / 11110.99.24.1

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 35% of the time in December, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 10% of December, with mostly cloudy or overcast conditions the remaining 55%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14654
24456
34456
44456
54456
64456
74456
84456
94555
104555
114456
124456
134456
144555
154555
164456
174555
184555
194654
204555
214555
224555
234654
244555
254555
264654
274654
284753
294753
304753
314852

Chance of precipitation in December

Any precipitation

Eiras gets around 111 mm of rain over 10.9 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 35% and peaks near 40% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
135
235
334
434
533
633
733
833
933
1033
1133
1233
1333
1433
1533
1633
1733
1834
1934
2034
2135
2236
2337
2437
2538
2638
2739
2839
2940
3040
3140

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

Most of December feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, December lands in the dry band about 94% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)
1946
2946
3955
4955
5955
6955
7955
8946
9946
10946
11946
12946
13946
14946
15946
16946
17946
18946
19946
20946
21946
22946
23946
24946
25946
26946
27946
28946
29946
30955
31955

Wind in December

Winds average 11 km/h in December, the windiest month of the year.

Across December, daily wind ranges from about 11 km/h on the calmest days to 12 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
111calm
211calm
311calm
411calm
511calm
611calm
711calm
811calm
911calm
1011calm
1111calm
1211calm
1311calm
1411calm
1511calm
1611calm
1711calm
1811calm
1911calm
2011calm
2111calm
2211calm
2311calm
2411calm
2512calm
2612calm
2712calm
2811calm
2911calm
3011calm
3111calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 h 18 min at the start of December to 9 h 12 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 6 minutes over December. Sunrise moves from 7:43 AM to 8:02 AM, and sunset from 5:04 PM to 5:12 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.37:435:04
29.37:445:04
39.37:455:03
49.37:465:03
59.37:475:03
69.37:485:03
79.27:495:03
89.27:495:03
99.27:505:03
109.27:515:03
119.27:525:03
129.27:535:03
139.27:535:04
149.27:545:04
159.27:555:04
169.17:555:04
179.17:565:05
189.17:575:05
199.17:575:05
209.17:585:06
219.17:585:06
229.17:595:07
239.17:595:07
249.18:005:08
259.18:005:08
269.18:005:09
279.18:015:09
289.18:015:10
299.28:015:11
309.28:025:11
319.28:025:12

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 1.81 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 1.81 kWh/m² to a high of 7.28 kWh/m² in July across the year — December's 1.81 kWh/m² sits near the bottom.

00.511.522.5151015202531
Solar energy (kWh/m²)Level
11.9Dim
21.9Dim
31.9Dim
41.9Dim
51.9Dim
61.9Dim
71.9Dim
81.9Dim
91.8Dim
101.8Dim
111.8Dim
121.8Dim
131.8Dim
141.8Dim
151.8Dim
161.8Dim
171.8Dim
181.8Dim
191.8Dim
201.8Dim
211.8Dim
221.8Dim
231.8Dim
241.8Dim
251.8Dim
261.8Dim
271.8Dim
281.8Dim
291.8Dim
301.8Dim
311.8Dim
Planning a trip in December

Hazard calendar for Eiras

In seasonPeak

In December, Eiras sits inside its rainy season season. The full year is below, with each hazard's peak months called out.

Eiras's rainy season runs October–May, when most of the year's rain falls.

Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is December a good time to visit Eiras?

Our two travel scores rate December for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

4.1
Sightseeing
11th-best month of the year
0.0
Beach & pool
11th-best month of the year

December is a reasonable time to visit Eiras for sightseeing.

What to pack for Eiras in December

From December's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In December, Eiras sees daytime highs around 14°C and nights near 7°C. Worth packing: a warm layer and rain gear. About 11 days see rain.

a warm layerrain gear

Sea temperature near Eiras in December

The nearest coast averages about 15°C in December — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 41 km away) is warmest in August at about 18°C and coldest in February near 14°C.

The water stays below 20°C all year — cool enough that most swimmers want a wetsuit.

12°14°16°18°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcool
Sea temperature (°C)Comfort
Jan14Bracing
Feb14Bracing
Mar14Bracing
Apr15Bracing
May16Cool
Jun18Cool
Jul18Cool
Aug18Cool
Sep18Cool
Oct17Cool
Nov16Cool
Dec15Bracing

UV index in Eiras in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 2. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Eiras peaks around July 14 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateLowJul 14UV 9Dec 21UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5High
Apr7High
May7High
Jun9Very high
Jul9Very high
Aug8Very high
Sep6High
Oct5Moderate
Nov2Moderate
Dec2Low

Air quality in Eiras in December

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where December falls, not just the annual average.

Air quality in Eiras is worst in October — around 29 µg/m³ PM2.5 (moderate), about 3.9× the cleanest month (November, 7 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodModerateModerateGoodOct 1228 µg/m³Nov 237 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb10Good
Mar13Moderate
Apr11Good
May8Good
Jun21Moderate
Jul9Good
Aug24Moderate
Sep23Moderate
Oct29Moderate
Nov7Good
Dec7Good
Location & terrain

Where is Eiras?

Eiras sits at 40.2°N, 8.4°W, 43 m above sea level, in Portugal. The nearest listed city is São Paulo de Frades, 2.0 km away.

Topography around Eiras

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Eiras.

Within 3 km, the terrain around Eiras has significant variations in elevation — a maximum elevation change of 253 m around an average of 92 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 559 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,993 m.

The land around Eiras is covered by trees (57%) within 3 km, trees (70%) within 16 km, and trees (55%) and grassland (21%) within 80 km.

3 km
253 m
16 km
559 m
80 km
1,993 m
treesshrubsgrasslandcroplandartificial surfaceswater
December weather nearby: São Paulo de Frades 2.0 km · Santo António dos Olivais 3.0 km · Coimbra 5.0 km · São Martinho do Bispo 6.0 km · Ribeira de Frades 7.0 km · Condeixa-a-Nova 17 km · Figueira da Foz 39 km · Pombal 41 km

Portugal travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type C / E / F
230 V · 50 Hz
Prices
≈ 60% of US
price level, 2025
GDP per capita
$32,082
2025
Happiness
6.0 / 10
World Happiness, 2025
Safe drinking water
95%
of population, 2024
Homicide rate
0.7
per 100k, 2022
Road deaths
8.2
per 100k/yr, 2019
Income group
High
World Bank
English
Very high
EF EPI 612
Religion
Catholic 68%not applicable 13%no religion 12%no response 2%

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 Eiras (40.2483°, -8.4155°, elevation 43 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. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).