Bastos weather in December

In December, Bastos sees average daytime highs of 31°C and overnight lows near 21°C, with 181 mm of rain across 19.4 wet days and about 13.3 hours of daylight. It is the 1st-warmest and 3rd-wettest month of the year here.

Day-to-day highs hold fairly steady near 31°C through the month. The sky is clear or mostly clear about 19% of the time in December, and the air most often feels oppressive.

Daylight stretches from about 13 h 12 min at the start of December to 13 h 18 min by month's end. Set against the rest of the year, December is Bastos's 11th-clearest and 8th-windiest month. For the whole year in context, see Bastos's year-round climate.

Daytime high
31°
1st warmest
Overnight low
21°
10th coldest
Rainfall
181 mm
19.4 wet days
Daylight
13 h 18 min
6:39 AM – 7:59 PM
Cloud cover
68%
11th clearest
Wind
9 km/h
8th windiest
Solar energy
6.03 kWh/m²
Travel score
3.6
out of 10

Bastos 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 31°C through the month.

A typical December day in Bastos reaches about 31°C in the afternoon and slips back to 21°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 27°C and 34°C. Set against its neighbours, December runs on par with November and on par with January.

15°20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
13121
23121
33121
43121
53121
63121
73121
83121
93121
103121
113121
123121
133121
143121
153121
163121
173121
183121
193121
203122
213122
223122
233122
243122
253122
263122
273122
283122
293122
303122
313022

How December really feels in Bastos

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.

Bastos weather by month

How December compares with the rest of the year at a glance. December is the 1st-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan30° / 22°23321.713.23.5
Feb30° / 22°18119.112.83.6
Mar30° / 21°13517.112.24.2
Apr29° / 19°647.911.55.7
May27° / 16°616.3117.3
Jun26° / 15°424.710.77.8
Jul27° / 15°263.610.88.0
Aug29° / 16°313.611.26.9
Sep30° / 18°767.711.95.4
Oct31° / 20°12012.512.54.4
Nov31° / 20°13614.4134.1
Dec31° / 21°18119.413.33.6

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 19% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 17% of December, with mostly cloudy or overcast conditions the remaining 64%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13763
23565
33466
43565
53367
63466
73466
83466
93466
103466
113565
123664
133664
143763
153763
163961
173961
184060
194060
204060
213961
223961
233862
243763
253763
263664
273466
283466
293367
303268
313169

Chance of precipitation in December

Any precipitation

Bastos gets around 181 mm of rain over 19.4 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 62% and peaks near 68% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%151015202531
Rain chance (%)
154
256
357
458
558
659
760
860
961
1061
1162
1262
1362
1462
1562
1663
1763
1863
1963
2063
2163
2264
2364
2465
2566
2666
2767
2867
2968
3068
3168

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 43% of days. Sticky, muggy-or-worse air turns up on roughly 83% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
128184130
227174132
327174134
426164135
526154136
625154138
725144039
825144040
914144040
1014144041
1114144042
1214143942
1314143942
1414143943
1504144043
1603134043
1703134043
1803134044
1903134044
2003134044
2102124045
2202124046
2302114046
2401114047
2501114048
2601103949
2701103950
2800103852
290093853
300093754
310093754

Wind in December

Winds average 9 km/h in December.

Across December, daily wind ranges from about 9 km/h on the calmest days to 9 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
19calm
29calm
39calm
49calm
59calm
69calm
79calm
89calm
99calm
109calm
119calm
129calm
139calm
149calm
159calm
169calm
179calm
189calm
199calm
209calm
219calm
229calm
239calm
249calm
259calm
269calm
279calm
289calm
299calm
309calm
319calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 13 h 12 min at the start of December to 13 h 18 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 6 minutes over December. Sunrise moves from 6:35 AM to 6:46 AM, and sunset from 7:50 PM to 8:06 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.26:357:50
213.36:367:51
313.36:367:51
413.36:367:52
513.36:367:53
613.36:367:53
713.36:367:54
813.36:377:54
913.36:377:55
1013.36:377:56
1113.36:377:56
1213.36:387:57
1313.36:387:57
1413.36:387:58
1513.36:397:59
1613.36:397:59
1713.36:408:00
1813.36:408:00
1913.36:408:01
2013.36:418:01
2113.36:418:02
2213.36:428:02
2313.36:428:03
2413.36:438:03
2513.36:438:03
2613.36:448:04
2713.36:448:04
2813.36:458:05
2913.36:458:05
3013.36:468:05
3113.36:468:06

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 6.03 kWh/m².

For context, solar energy here swings from a low near 3.67 kWh/m² to a high of 6.14 kWh/m² in November across the year — December's 6.03 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
16.1Intense
26.1Intense
36.0Intense
46.0Intense
56.0Intense
66.0Intense
76.0Bright
86.0Bright
96.0Bright
106.0Bright
116.0Bright
126.0Intense
136.0Intense
146.0Intense
156.0Intense
166.0Intense
176.1Intense
186.1Intense
196.1Intense
206.1Intense
216.1Intense
226.1Intense
236.1Intense
246.1Intense
256.0Intense
266.0Intense
276.0Intense
286.0Bright
295.9Bright
305.9Bright
315.9Bright
Planning a trip in December

Hazard calendar for Bastos

In seasonPeak

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

Bastos's rainy season runs October–March, 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 Bastos?

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

3.6
Sightseeing
10th-best month of the year
5.2
Beach & pool
10th-best month of the year

December is a weaker month for outdoor sightseeing in Bastos.

What to pack for Bastos in December

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

In December, Bastos sees daytime highs around 31°C and nights near 21°C. Pack light clothes, rain gear and sun protection. About 19 days see rain.

light clothesrain gearsun protection

UV index in Bastos in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 14 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Bastos peaks around January 20 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 12 at about 6 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highHighVery highExtremeJan 20UV 15Jul 12UV 6
UV index (midday)Level
Jan15Extreme
Feb15Extreme
Mar13Extreme
Apr10Very high
May7Very high
Jun6High
Jul6High
Aug8Very high
Sep8Very high
Oct11Extreme
Nov13Extreme
Dec14Extreme

Air quality in Bastos 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 Bastos is worst in September — around 19 µg/m³ PM2.5 (moderate), about 2.8× the cleanest month (November, 7 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodSep 1718 µg/m³Nov 237 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb8Good
Mar7Good
Apr8Good
May9Good
Jun8Good
Jul8Good
Aug12Good
Sep19Moderate
Oct13Moderate
Nov7Good
Dec7Good
Location & terrain

Where is Bastos?

Bastos sits at 21.9°S, 50.7°W, 460 m above sea level, in Brazil. The nearest listed city is Osvaldo Cruz, 20 km away.

Topography around Bastos

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

Within 3 km, the terrain around Bastos has only modest variations in elevation — a maximum elevation change of 126 m around an average of 456 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 211 m; within 80 km, significant variations in elevation — a maximum elevation change of 417 m.

The land around Bastos is covered by cropland (33%), grassland (29%) and trees (21%) within 3 km, cropland (55%) and grassland (28%) within 16 km, and cropland (53%) and grassland (33%) within 80 km.

3 km
126 m
16 km
211 m
80 km
417 m
treesgrasslandcroplandartificial surfacesbare terrain
December weather nearby: Osvaldo Cruz 20 km · Tupã 23 km · Lucélia 37 km · Rancharia 38 km · Adamantina 44 km · Martinópolis 51 km · Paraguaçu Paulista 57 km · Pompéia 62 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 Bastos (-21.9219°, -50.7339°, elevation 460 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. 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).