Santa Rosa weather in December

In December, Santa Rosa sees average daytime highs of 31°C and overnight lows near 20°C, with 160 mm of rain across 13.1 wet days and about 13.7 hours of daylight. It is the 2nd-warmest and 2nd-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 41% of the time in December, and the air most often feels muggy.

Daylight stretches from about 13 h 36 min at the start of December to 13 h 42 min by month's end. Set against the rest of the year, December is Santa Rosa's 7th-clearest and 8th-windiest month. For the whole year in context, see Santa Rosa's year-round climate.

Daytime high
31°
2nd warmest
Overnight low
20°
10th coldest
Rainfall
160 mm
13.1 wet days
Daylight
13 h 48 min
6:41 AM – 8:27 PM
Cloud cover
54%
7th clearest
Wind
10 km/h
8th windiest
Solar energy
6.63 kWh/m²
Travel score
4.3
out of 10

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 Santa Rosa reaches about 31°C in the afternoon and slips back to 20°C overnight — a 11°C spread between the day's warmth and the night's chill. On most days the high lands between 26°C and 35°C. Set against its neighbours, December runs about 2°C warmer than November and on par with January.

15°20°25°30°35°40°151015202531
Avg high (°C)Avg low (°C)
13019
23019
33019
43019
53019
63019
73119
83119
93119
103120
113120
123120
133120
143120
153120
163120
173120
183120
193120
203120
213120
223120
233120
243121
253121
263121
273121
283121
293121
303121
313121

How December really feels in Santa Rosa

Once humidity and wind are folded in, December averages 14 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
14
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.

Santa Rosa weather by month

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

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan31° / 21°14314.513.63.9
Feb31° / 21°13614134.2
Mar30° / 19°12711.812.25.0
Apr27° / 17°1559.711.46.6
May23° / 13°1529.410.66.9
Jun21° / 12°1439.710.36.5
Jul20° / 11°1379.410.46.6
Aug23° / 12°948.5117.3
Sep25° / 14°15210.411.87.0
Oct27° / 16°21512.912.76.1
Nov29° / 18°1561113.45.5
Dec31° / 20°16013.113.74.3

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 41% 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 46%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15545
25446
35446
45446
55347
65347
75347
85347
95446
105446
115446
125446
135446
145446
155446
165446
175545
185545
195644
205644
215545
225545
235545
245446
255446
265446
275446
285446
295446
305446
315446

Chance of precipitation in December

Any precipitation

Santa Rosa gets around 160 mm of rain over 13.1 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 42% and peaks near 46% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%151015202531
Rain chance (%)
139
240
340
440
540
640
740
840
940
1040
1140
1240
1340
1440
1541
1641
1741
1842
1942
2042
2143
2243
2344
2445
2545
2646
2746
2846
2946
3046
3146

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 36% of days. Sticky, muggy-or-worse air turns up on roughly 58% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
19172735110
29172735110
39162736120
49162736120
59152736130
69152737130
78152637140
88142637140
98142637150
108142637160
117132637160
127132637170
137132537180
146132537190
156122537200
166122437210
175122437220
185112337230
195112337240
205112237250
215102237270
224102236280
23492136290
24492136301
25492035321
26492034331
27382034341
28382033351
29382032361
30382031371
31382031371

Wind in December

Winds average 10 km/h in December.

Across December, daily wind ranges from about 10 km/h on the calmest days to 10 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
110calm
210calm
310calm
410calm
510calm
610calm
710calm
810calm
910calm
1010calm
1110calm
1210calm
1310calm
1410calm
1510calm
1610calm
1710calm
1810calm
1910calm
2010calm
2110calm
2210calm
2310calm
2410calm
2510calm
2610calm
2710calm
2810calm
2910calm
3010calm
3110calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 13 h 36 min at the start of December to 13 h 42 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 6:39 AM to 6:49 AM, and sunset from 8:17 PM to 8:33 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.66:398:17
213.76:398:18
313.76:398:18
413.76:398:19
513.76:398:20
613.76:398:20
713.76:398:21
813.76:398:22
913.76:398:22
1013.76:408:23
1113.76:408:24
1213.76:408:24
1313.76:408:25
1413.76:418:26
1513.86:418:26
1613.86:418:27
1713.86:428:27
1813.86:428:28
1913.86:438:28
2013.86:438:29
2113.86:438:29
2213.86:448:30
2313.86:448:30
2413.86:458:31
2513.86:458:31
2613.86:468:32
2713.86:468:32
2813.86:478:32
2913.86:488:33
3013.76:488:33
3113.76:498:33

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 6.63 kWh/m² — the sunniest month for solar.

For context, solar energy here swings from a low near 2.61 kWh/m² to a high of 6.63 kWh/m² in December across the year — December's 6.63 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
16.6Intense
26.6Intense
36.6Intense
46.6Intense
56.6Intense
66.6Intense
76.6Intense
86.6Intense
96.6Intense
106.7Intense
116.7Intense
126.7Intense
136.7Intense
146.7Intense
156.7Intense
166.7Intense
176.7Intense
186.7Intense
196.7Intense
206.7Intense
216.7Intense
226.7Intense
236.6Intense
246.6Intense
256.6Intense
266.6Intense
276.6Intense
286.6Intense
296.6Intense
306.6Intense
316.7Intense
Planning a trip in December

Is December a good time to visit Santa Rosa?

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
6.3
Beach & pool
4th-best month of the year

December is a reasonable time to visit Santa Rosa for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Santa Rosa in December

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

In December, Santa Rosa sees daytime highs around 31°C and nights near 20°C. Pack light clothes and sun protection. Worth having: rain gear. About 13 days see rain.

light clothessun protectionrain gear

UV index in Santa Rosa 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 Santa Rosa peaks around January 20 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 21 at about 4 (moderate).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highModerateVery highExtremeJan 20UV 14Jun 21UV 4
UV index (midday)Level
Jan14Extreme
Feb13Extreme
Mar11Extreme
Apr8Very high
May5High
Jun4Moderate
Jul4Moderate
Aug5High
Sep8Very high
Oct7Very high
Nov11Extreme
Dec12Extreme

Air quality in Santa Rosa 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 Santa Rosa is worst in September — around 17 µg/m³ PM2.5 (moderate), about 2.5× the cleanest month (March, 7 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodSep 1516 µg/m³Mar 137 µg/m³
PM2.5 (µg/m³)Level
Jan7Good
Feb7Good
Mar7Good
Apr8Good
May7Good
Jun7Good
Jul8Good
Aug13Moderate
Sep17Moderate
Oct11Good
Nov8Good
Dec7Good
Location & terrain

Where is Santa Rosa?

Santa Rosa sits at 27.9°S, 54.5°W, 284 m above sea level, in Brazil. The nearest listed city is Santo Cristo, 19 km away.

Topography around Santa Rosa

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

Within 3 km, the terrain around Santa Rosa has only modest variations in elevation — a maximum elevation change of 137 m around an average of 273 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 268 m; within 80 km, significant variations in elevation — a maximum elevation change of 487 m.

The land around Santa Rosa is covered by trees (37%) and artificial surfaces (32%) within 3 km, cropland (61%) and trees (29%) within 16 km, and cropland (47%) and trees (39%) within 80 km.

3 km
137 m
16 km
268 m
80 km
487 m
treesgrasslandcroplandartificial surfacesbare terrainwater
December weather nearby: Santo Cristo 19 km · Giruá 22 km · Três de Maio 26 km · Horizontina 32 km · Santo Ângelo 52 km · El Soberbio 70 km · Três Passos 71 km · Oberá 76 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 Santa Rosa (-27.8708°, -54.4814°, elevation 284 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).