Castelo do Piauí weather in December

In December, Castelo do Piauí sees average daytime highs of 36°C and overnight lows near 25°C, with 41 mm of rain across 6.7 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 6th-wettest month of the year here.

Day-to-day highs hold fairly steady near 36°C through the month. The sky is clear or mostly clear about 29% of the time in December, and the air most often feels humid.

Daylight stretches from about 12 h 18 min at the start of December to 12 h 18 min by month's end. Set against the rest of the year, December is Castelo do Piauí's 7th-clearest and 7th-windiest month. For the whole year in context, see Castelo do Piauí's year-round climate.

Daytime high
36°
4th warmest
Overnight low
25°
11th coldest
Rainfall
41 mm
6.7 wet days
Daylight
12 h 18 min
5:33 AM – 5:52 PM
Cloud cover
59%
7th clearest
Wind
11 km/h
7th windiest
Solar energy
6.04 kWh/m²
Travel score
2.4
out of 10

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 36°C through the month.

A typical December day in Castelo do Piauí reaches about 36°C in the afternoon and slips back to 25°C overnight — a 11°C spread between the day's warmth and the night's chill. On most days the high lands between 33°C and 38°C. Set against its neighbours, December runs about 1°C cooler than November and about 2°C warmer than January.

20°25°30°35°40°151015202531
Avg high (°C)Avg low (°C)
13625
23625
33625
43625
53625
63625
73625
83625
93625
103625
113625
123625
133625
143625
153625
163625
173625
183625
193525
203525
213525
223525
233525
243525
253525
263525
273525
283525
293525
303525
313525

How December really feels in Castelo do Piauí

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.

Castelo do Piauí weather by month

How December compares with the rest of the year at a glance. December is the 4th-warmest and 6th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan33° / 24°15616.512.32.8
Feb32° / 23°17917.112.22.9
Mar32° / 23°25721.8122.9
Apr32° / 23°18418.311.93.3
May32° / 23°768.811.83.9
Jun33° / 23°11211.74.2
Jul34° / 23°61.111.74.0
Aug35° / 24°10.111.83.3
Sep36° / 24°10.3122.5
Oct37° / 25°140.812.12.0
Nov37° / 25°142.612.22.1
Dec36° / 25°416.712.32.4

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 29% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 23% of December, with mostly cloudy or overcast conditions the remaining 48%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15743
25743
35743
45743
55743
65842
75743
85743
95644
105644
115545
125545
135446
145446
155446
165347
175347
185248
195149
205149
215050
224852
234852
244753
254753
264555
274555
284456
294456
304258
314159

Chance of precipitation in December

Any precipitation

Castelo do Piauí gets around 41 mm of rain over 6.7 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 22% and peaks near 36% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%50%151015202531
Rain chance (%)
113
214
314
415
515
616
717
817
918
1019
1119
1220
1320
1420
1521
1621
1722
1822
1923
2023
2124
2225
2325
2426
2527
2629
2730
2831
2933
3034
3136

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, December lands in the humid band about 46% of days. Sticky, muggy-or-worse air turns up on roughly 47% of them.

0%25%50%75%100%151015202531
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
11256275
21157275
31157266
41157266
51057267
61057267
7957277
8956278
9857278
10855289
11755299
127542910
137533010
147513111
157503211
167493312
177473412
187453513
197443613
207423714
217413815
227393816
237383917
246363918
256344019
266334021
276314122
286294124
295284225
305264227
315244229

Wind in December

Winds average 11 km/h in December.

Across December, daily wind ranges from about 9 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
112light breeze
212light breeze
312calm
412calm
512calm
612calm
712calm
812calm
912calm
1012calm
1112calm
1211calm
1311calm
1411calm
1511calm
1611calm
1711calm
1811calm
1911calm
2011calm
2111calm
2211calm
2311calm
2410calm
2510calm
2610calm
2710calm
2810calm
2910calm
3010calm
319calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 12 h 18 min at the start of December to 12 h 18 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 5:45 PM to 5:59 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.35:275:45
212.35:285:45
312.35:285:45
412.35:285:46
512.35:295:46
612.35:295:47
712.35:295:47
812.35:305:48
912.35:305:48
1012.35:315:49
1112.35:315:49
1212.35:315:50
1312.35:325:50
1412.35:325:51
1512.35:335:51
1612.35:335:52
1712.35:345:52
1812.35:345:53
1912.35:355:53
2012.35:355:53
2112.35:355:54
2212.35:365:54
2312.35:365:55
2412.35:375:55
2512.35:375:56
2612.35:385:56
2712.35:385:57
2812.35:395:57
2912.35:395:58
3012.35:405:58
3112.35:405:59

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 6.04 kWh/m².

For context, solar energy here swings from a low near 4.99 kWh/m² to a high of 6.94 kWh/m² in October across the year — December's 6.04 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
16.4Intense
26.3Intense
36.3Intense
46.3Intense
56.3Intense
66.3Intense
76.3Intense
86.2Intense
96.2Intense
106.2Intense
116.1Intense
126.1Intense
136.1Intense
146.0Intense
156.0Intense
166.0Intense
176.0Bright
186.0Bright
195.9Bright
205.9Bright
215.9Bright
225.9Bright
235.8Bright
245.8Bright
255.8Bright
265.8Bright
275.8Bright
285.7Bright
295.7Bright
305.7Bright
315.7Bright
Planning a trip in December

Hazard calendar for Castelo do Piauí

In seasonPeak

None of Castelo do Piauí's seasonal hazards are active in December. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Castelo do Piauí's monsoon runs January–April, when most of the year's rain falls.

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

Is December a good time to visit Castelo do Piauí?

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

2.4
Sightseeing
10th-best month of the year
5.4
Beach & pool
7th-best month of the year

December is a weaker month for outdoor sightseeing in Castelo do Piauí.

What to pack for Castelo do Piauí in December

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

In December, Castelo do Piauí sees daytime highs around 36°C and nights near 25°C. Pack light clothes and sun protection. About 7 days see rain.

light clothessun protection

UV index in Castelo do Piauí in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 11 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Castelo do Piauí peaks around March 15 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 24 at about 10 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeExtremeMar 15UV 15Jul 24UV 10
UV index (midday)Level
Jan13Extreme
Feb14Extreme
Mar15Extreme
Apr14Extreme
May11Extreme
Jun10Extreme
Jul10Very high
Aug10Very high
Sep12Extreme
Oct12Extreme
Nov12Extreme
Dec11Extreme
Location & terrain

Where is Castelo do Piauí?

Castelo do Piauí sits at 5.3°S, 41.6°W, 241 m above sea level, in Brazil. The nearest listed city is São Miguel do Tapuio, 32 km away.

Topography around Castelo do Piauí

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

Within 3 km, the terrain around Castelo do Piauí has only modest variations in elevation — a maximum elevation change of 82 m around an average of 249 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 300 m; within 80 km, large variations in elevation — a maximum elevation change of 790 m.

The land around Castelo do Piauí is covered by shrubs (67%) within 3 km, shrubs (63%) and trees (31%) within 16 km, and shrubs (65%) and trees (27%) within 80 km.

3 km
82 m
16 km
300 m
80 km
790 m
treesshrubsgrasslandcroplandartificial surfaces
December weather nearby: São Miguel do Tapuio 32 km · Campo Maior 88 km · Novo Oriente 89 km · Crateús 99 km · Pedro II 100 km · Altos 105 km · Quiterianópolis 111 km · Piripiri 119 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 Castelo do Piauí (-5.3222°, -41.5525°, elevation 241 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).