Oeiras weather in December

In December, Oeiras sees average daytime highs of 34°C and overnight lows near 25°C, with 81 mm of rain across 10.7 wet days and about 12.4 hours of daylight. It is the 5th-warmest and 5th-wettest month of the year here.

Day-to-day highs hold fairly steady near 34°C through the month. The sky is clear or mostly clear about 26% of the time in December, and the air most often feels oppressive.

Daylight stretches from about 12 h 24 min at the start of December to 12 h 24 min by month's end. Set against the rest of the year, December is Oeiras's 8th-clearest and 9th-windiest month. For the whole year in context, see Oeiras's year-round climate.

Daytime high
34°
5th warmest
Overnight low
25°
9th coldest
Rainfall
81 mm
10.7 wet days
Daylight
12 h 24 min
5:33 AM – 5:57 PM
Cloud cover
62%
8th clearest
Wind
7 km/h
9th windiest
Solar energy
5.61 kWh/m²
Travel score
2.9
out of 10

Oeiras is human settlement in Brazil.

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 34°C through the month.

A typical December day in Oeiras reaches about 34°C in the afternoon and slips back to 25°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 30°C and 37°C. Set against its neighbours, December runs about 2°C cooler than November and about 2°C warmer than January.

20°25°30°35°40°151015202531
Avg high (°C)Avg low (°C)
13526
23526
33426
43426
53425
63425
73425
83425
93425
103425
113425
123425
133425
143425
153425
163425
173425
183425
193425
203425
213425
223425
233425
243425
253425
263425
273325
283325
293325
303325
313324

How December really feels in Oeiras

Once humidity and wind are folded in, December averages 31 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
31
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

The story in December is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Oeiras weather by month

How December compares with the rest of the year at a glance. December is the 5th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan32° / 24°16519.712.43.0
Feb32° / 23°16618.212.23.1
Mar32° / 23°16120.5123.2
Apr32° / 24°9013.211.83.6
May33° / 24°334.811.73.8
Jun33° / 24°30.511.64.2
Jul34° / 23°20.411.64.1
Aug35° / 24°00.111.83.4
Sep36° / 25°10.2122.4
Oct37° / 27°14212.22.0
Nov35° / 26°446.212.32.5
Dec34° / 25°8110.712.42.9

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 26% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 21% of December, with mostly cloudy or overcast conditions the remaining 53%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15248
25347
35347
45347
55347
65248
75248
85149
95149
105149
115149
125050
135050
144951
154951
164852
174753
184753
194555
204555
214357
224357
234357
244159
254159
264060
274060
283961
293961
303961
313862

Chance of precipitation in December

Any precipitation

Oeiras gets around 81 mm of rain over 10.7 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 36% and peaks near 49% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%151015202531
Rain chance (%)
126
226
327
427
528
628
729
830
931
1031
1132
1233
1334
1435
1536
1636
1737
1837
1938
2038
2138
2239
2340
2440
2541
2643
2744
2845
2946
3048
3149

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, December lands in the oppressive band about 47% of days. Sticky, muggy-or-worse air turns up on roughly 84% of them.

0%25%50%75%100%151015202531
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
13194136
23184137
33184237
43184238
53174238
62174139
72174139
82164140
92164141
102154141
112154142
122154043
131144044
141144044
151134045
161133946
171133947
181133848
191123749
201123750
211123651
221123552
231123453
241113355
251113256
261113157
271103059
281102960
29192862
30292762
31282664

Wind in December

Winds average 7 km/h in December.

Across December, daily wind ranges from about 6 km/h on the calmest days to 7 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
276calm
286calm
296calm
306calm
316calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 12 h 24 min at the start of December to 12 h 24 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 0 minutes over December. Sunrise moves from 5:27 AM to 5:40 AM, and sunset from 5:50 PM to 6:04 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.45:275:50
212.45:275:50
312.45:285:51
412.45:285:51
512.45:285:52
612.45:295:52
712.45:295:52
812.45:295:53
912.45:305:53
1012.45:305:54
1112.45:305:54
1212.45:315:55
1312.45:315:55
1412.45:325:56
1512.45:325:56
1612.45:335:57
1712.45:335:57
1812.45:335:58
1912.45:345:58
2012.45:345:59
2112.45:355:59
2212.45:356:00
2312.45:366:00
2412.45:366:01
2512.45:376:01
2612.45:376:02
2712.45:386:02
2812.45:386:02
2912.45:396:03
3012.45:396:03
3112.45:406:04

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 5.61 kWh/m².

For context, solar energy here swings from a low near 4.96 kWh/m² to a high of 6.77 kWh/m² in September across the year — December's 5.61 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.8Bright
25.8Bright
35.8Bright
45.8Bright
55.8Bright
65.8Bright
75.7Bright
85.7Bright
95.7Bright
105.7Bright
115.7Bright
125.7Bright
135.6Bright
145.6Bright
155.6Bright
165.6Bright
175.6Bright
185.5Bright
195.5Bright
205.5Bright
215.5Bright
225.5Bright
235.5Bright
245.5Bright
255.4Bright
265.4Bright
275.4Bright
285.4Bright
295.4Bright
305.3Bright
315.3Bright
Planning a trip in December

Hazard calendar for Oeiras

In seasonPeak

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

Oeiras's rainy season runs December–April, 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 Oeiras?

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

2.9
Sightseeing
9th-best month of the year
5.7
Beach & pool
7th-best month of the year

December is a weaker month for outdoor sightseeing in Oeiras.

What to pack for Oeiras in December

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

In December, Oeiras sees daytime highs around 34°C and nights near 25°C. Pack light clothes. Worth having: rain gear and sun protection. About 11 days see rain.

light clothesrain gearsun protection

UV index in Oeiras in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 12 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Oeiras peaks around March 10 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 23 at about 10 (very high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highExtremeMar 10UV 15Jun 23UV 10
UV index (midday)Level
Jan14Extreme
Feb15Extreme
Mar15Extreme
Apr13Extreme
May11Extreme
Jun10Very high
Jul10Very high
Aug10Very high
Sep12Extreme
Oct12Extreme
Nov12Extreme
Dec12Extreme
Location & terrain

Where is Oeiras?

Oeiras sits at 7.0°S, 42.1°W, 181 m above sea level, in Brazil. The nearest listed city is Picos, 74 km away.

Topography around Oeiras

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

Within 3 km, the terrain around Oeiras has only modest variations in elevation — a maximum elevation change of 114 m around an average of 196 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 173 m; within 80 km, significant variations in elevation — a maximum elevation change of 468 m.

The land around Oeiras is covered by shrubs (53%) within 3 km, shrubs (68%) and trees (24%) within 16 km, and shrubs (56%) and trees (33%) within 80 km.

3 km
114 m
16 km
173 m
80 km
468 m
treesshrubsgrasslandcroplandartificial surfaces
December weather nearby: Picos 74 km · Valença do Piauí 81 km · Floriano 103 km · Barão de Grajaú 103 km · Regeneração 108 km · Jaicós 116 km · Amarante 117 km · Água Branca 138 km

Brazil travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / N
127 / 220 V · 60 Hz
Prices
≈ 46% of US
price level, 2025
GDP per capita
$10,713
2025
Happiness
6.6 / 10
World Happiness, 2025
Safe drinking water
89%
of population, 2024
Homicide rate
19.3
per 100k, 2023
Road deaths
16
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Low
EF EPI 482
Religion
Roman Catholic 57%Evangelical 27%none 9%other 4%

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 Oeiras (-7.0253°, -42.1311°, elevation 181 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. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).