Rio Claro weather in December

In December, Rio Claro sees average daytime highs of 28°C and overnight lows near 20°C, with 237 mm of rain across 23.1 wet days and about 13.4 hours of daylight. It is the 4th-warmest and 2nd-wettest month of the year here.

Day-to-day highs hold fairly steady near 28°C through the month. The sky is clear or mostly clear about 10% of the time in December, and the air most often feels muggy.

Daylight stretches from about 13 h 18 min at the start of December to 13 h 24 min by month's end. Set against the rest of the year, December is Rio Claro's 11th-clearest and 5th-windiest month. For the whole year in context, see Rio Claro's year-round climate.

Daytime high
28°
4th warmest
Overnight low
20°
10th coldest
Rainfall
237 mm
23.1 wet days
Daylight
13 h 24 min
6:11 AM – 7:34 PM
Cloud cover
77%
11th clearest
Wind
5 km/h
5th windiest
Solar energy
5.52 kWh/m²
Travel score
4.3
out of 10

Rio Claro is Place in Brasil.

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 28°C through the month.

A typical December day in Rio Claro reaches about 28°C in the afternoon and slips back to 20°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 23°C and 32°C. Set against its neighbours, December runs about 1°C warmer than November and about 1°C cooler than January.

15°20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
12719
22719
32720
42720
52720
62720
72720
82720
92720
102720
112720
122720
132820
142820
152820
162820
172820
182820
192820
202820
212820
222820
232820
242820
252820
262820
272820
282820
292821
302821
312821

Rio Claro weather by month

How December compares with the rest of the year at a glance. December is the 4th-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan29° / 21°2952413.23.8
Feb29° / 21°2042012.83.9
Mar28° / 20°20122.812.24.4
Apr26° / 19°10214.111.55.9
May24° / 16°6310.710.96.8
Jun24° / 15°356.710.67.6
Jul23° / 14°40710.77.6
Aug24° / 15°367.311.27.6
Sep25° / 16°7812.111.96.4
Oct26° / 18°11516.112.55.5
Nov26° / 19°18820.413.14.8
Dec28° / 20°23723.113.44.3

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 10% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 13% of December, with mostly cloudy or overcast conditions the remaining 77%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
12080
21981
31882
41882
51882
61882
71981
81981
91981
102080
112080
122179
132278
142377
152377
162476
172476
182476
192674
202674
212773
222773
232872
242773
252773
262773
272674
282575
292575
302575
312476

Chance of precipitation in December

Any precipitation

Rio Claro gets around 237 mm of rain over 23.1 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 74% and peaks near 81% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%151015202531
Rain chance (%)
168
268
368
468
569
669
769
869
969
1070
1170
1271
1372
1473
1573
1674
1775
1876
1977
2077
2178
2279
2379
2480
2580
2681
2781
2881
2981
3081
3181

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, December lands in the muggy band about 67% of days. Sticky, muggy-or-worse air turns up on roughly 85% of them.

0%25%50%75%100%151015202531
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
13246310
23236410
33226411
42216512
52206612
62206513
72196514
82186614
92186515
101176715
111166716
121156816
131156816
141146817
151136917
161136818
170127018
180126919
190117019
200116920
210107020
220106921
23097021
24096922
25086923
26086824
27086725
28086626
29086626
30086527
31076627

Wind in December

Winds average 5 km/h in December.

Across December, daily wind ranges from about 5 km/h on the calmest days to 5 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm
315calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 13 h 18 min at the start of December to 13 h 24 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 6:07 AM to 6:18 AM, and sunset from 7:25 PM to 7:41 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.36:077:25
213.36:087:26
313.36:087:26
413.36:087:27
513.36:087:28
613.36:087:28
713.36:087:29
813.36:097:30
913.46:097:30
1013.46:097:31
1113.46:097:31
1213.46:107:32
1313.46:107:33
1413.46:107:33
1513.46:117:34
1613.46:117:34
1713.46:117:35
1813.46:127:35
1913.46:127:36
2013.46:137:36
2113.46:137:37
2213.46:147:37
2313.46:147:38
2413.46:157:38
2513.46:157:39
2613.46:167:39
2713.46:167:40
2813.46:177:40
2913.46:177:40
3013.46:187:41
3113.46:187:41

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 5.52 kWh/m².

For context, solar energy here swings from a low near 3.4 kWh/m² to a high of 5.71 kWh/m² in February across the year — December's 5.52 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.4Bright
25.4Bright
35.4Bright
45.4Bright
55.4Bright
65.4Bright
75.4Bright
85.4Bright
95.4Bright
105.4Bright
115.4Bright
125.4Bright
135.4Bright
145.5Bright
155.5Bright
165.5Bright
175.5Bright
185.5Bright
195.5Bright
205.5Bright
215.5Bright
225.5Bright
235.5Bright
245.5Bright
255.5Bright
265.5Bright
275.5Bright
285.5Bright
295.5Bright
305.5Bright
315.5Bright
Planning a trip in December

Hazard calendar for Rio Claro

In seasonPeak

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

Rio Claro's rainy season runs November–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 Rio Claro?

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

4.3
Sightseeing
10th-best month of the year
4.6
Beach & pool
12th-best month of the year

December is a reasonable time to visit Rio Claro for sightseeing.

What to pack for Rio Claro in December

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

In December, Rio Claro sees daytime highs around 28°C and nights near 20°C. Pack light clothes and rain gear. Worth having: sun protection. About 23 days see rain.

light clothesrain gearsun protection

Sea temperature near Rio Claro in December

The nearest coast averages about 25°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 51 km away) is warmest in February at about 27°C and coldest in August near 21°C.

The water stays above 20°C all year — warm enough for a swim any month.

20°22°24°26°28°JanFebMarAprMayJunJulAugSepOctNovDeccoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan27Warm
Feb27Warm
Mar27Warm
Apr26Warm
May24Warm
Jun23Refreshing
Jul22Refreshing
Aug21Refreshing
Sep22Refreshing
Oct23Refreshing
Nov23Refreshing
Dec25Warm

UV index in Rio Claro 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 Rio Claro peaks around February 9 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 12 at about 5 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highHighVery highExtremeFeb 9UV 14Jul 12UV 5
UV index (midday)Level
Jan14Extreme
Feb14Extreme
Mar12Extreme
Apr9Very high
May7High
Jun6High
Jul5High
Aug8Very high
Sep7High
Oct11Extreme
Nov13Extreme
Dec14Extreme

Air quality in Rio Claro 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 Rio Claro is worst in September — around 33 µg/m³ PM2.5 (moderate), about 2.1× the cleanest month (December, 15 µg/m³).

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

010203040JanFebMarAprMayJunJulAugSepOctNovDecModerateSep 1332 µg/m³Dec 2115 µg/m³
PM2.5 (µg/m³)Level
Jan16Moderate
Feb16Moderate
Mar17Moderate
Apr19Moderate
May24Moderate
Jun29Moderate
Jul31Moderate
Aug27Moderate
Sep33Moderate
Oct20Moderate
Nov17Moderate
Dec15Moderate
Location & terrain

Where is Rio Claro?

Rio Claro sits at 22.7°S, 44.1°W, 464 m above sea level, in Brazil. The nearest listed city is Barra Mansa, 20 km away.

Topography around Rio Claro

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

Within 3 km, the terrain around Rio Claro has large variations in elevation — a maximum elevation change of 814 m around an average of 583 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,265 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,761 m.

The land around Rio Claro is covered by trees (50%) and grassland (48%) within 3 km, grassland (56%) and trees (43%) within 16 km, and trees (43%), grassland (29%) and water (24%) within 80 km.

3 km
814 m
16 km
1,265 m
80 km
2,761 m
treesgrasslandartificial surfaceswater
December weather nearby: Barra Mansa 20 km · Volta Redonda 22 km · Piraí 27 km · Pinheiral 27 km · Mangaratiba 28 km · Angra dos Reis 37 km · Porto Real 37 km · Itaguaí 40 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 Rio Claro (-22.7231°, -44.1356°, elevation 464 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).