São Jerônimo weather in December

In December, São Jerônimo sees average daytime highs of 29°C and overnight lows near 19°C, with 118 mm of rain across 11.8 wet days and about 13.9 hours of daylight. It is the 3rd-warmest and 9th-wettest month of the year here.

Highs climb over the month, from about 28°C in the first days to 30°C by the end. The sky is clear or mostly clear about 35% of the time in December, and the air most often feels muggy.

Daylight stretches from about 13 h 48 min at the start of December to 13 h 54 min by month's end. Set against the rest of the year, December is São Jerônimo's 3rd-clearest and 4th-windiest month. For the whole year in context, see São Jerônimo's year-round climate.

Daytime high
29°
3rd warmest
Overnight low
19°
9th coldest
Rainfall
118 mm
11.8 wet days
Daylight
13 h 54 min
6:26 AM – 8:21 PM
Cloud cover
56%
3rd clearest
Wind
11 km/h
4th windiest
Solar energy
6.48 kWh/m²
Travel score
5.2
out of 10

São Jerônimo is 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

Highs climb over the month, from about 28°C in the first days to 30°C by the end.

A typical December day in São Jerônimo reaches about 29°C in the afternoon and slips back to 19°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 25°C and 34°C. Set against its neighbours, December runs about 2°C warmer than November and about 1°C cooler than January.

10°15°20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
12818
22818
32818
42818
52818
62918
72918
82918
92919
102919
112919
122919
132919
142919
152919
162919
172919
182919
193019
203019
213020
223020
233020
243020
253020
263020
273020
283020
293020
303020
313020

São Jerônimo weather by month

How December compares with the rest of the year at a glance. December is the 3rd-warmest and 9th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan30° / 21°1281413.74.6
Feb30° / 20°11812.613.14.7
Mar28° / 19°1051112.25.8
Apr25° / 16°1089.211.36.9
May21° / 13°1118.810.56.7
Jun19° / 11°1199.310.16.1
Jul19° / 10°1441010.36.1
Aug21° / 11°1191010.96.5
Sep22° / 13°14911.311.86.3
Oct24° / 15°17012.112.76.4
Nov27° / 17°12110.113.56.5
Dec29° / 19°11811.813.95.2

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 35% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 18% of December, with mostly cloudy or overcast conditions the remaining 47%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15446
25446
35446
45347
55446
65446
75347
85347
95248
105248
115347
125347
135347
145347
155347
165248
175248
185248
195347
205347
215347
225347
235347
245347
255347
265347
275248
285347
295347
305347
315347

Chance of precipitation in December

Any precipitation

São Jerônimo gets around 118 mm of rain over 11.8 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 38% and peaks near 41% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
136
236
336
436
536
636
736
837
937
1037
1137
1237
1338
1438
1538
1638
1738
1839
1939
2039
2139
2239
2339
2439
2539
2639
2740
2840
2940
3040
3141

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 53% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1921323160
2821323270
3821323270
4820323270
5819323280
6819323380
7818323390
8817323390
98173234100
107173134100
117163135110
127163035120
136153036130
146152937140
156142837150
166132738160
176132738170
185122638180
195122538190
205122538210
215112438220
224112338230
234102338241
244102338251
253102238261
26392237271
27392237281
28392237291
29292237291
30282237301
31282237301

Wind in December

Winds average 11 km/h in December.

Across December, daily wind ranges from about 11 km/h on the calmest days to 11 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
111calm
211calm
311calm
411calm
511calm
611calm
711calm
811calm
911calm
1011calm
1111calm
1211calm
1311calm
1411calm
1511calm
1611calm
1711calm
1811calm
1911calm
2011calm
2111calm
2211calm
2311calm
2411calm
2511calm
2611calm
2711calm
2811calm
2911calm
3011calm
3111calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 13 h 48 min at the start of December to 13 h 54 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 6:23 AM to 6:33 AM, and sunset from 8:10 PM to 8:27 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.86:238:10
213.86:238:11
313.86:238:12
413.86:238:13
513.86:238:13
613.86:238:14
713.96:238:15
813.96:238:15
913.96:248:16
1013.96:248:17
1113.96:248:17
1213.96:248:18
1313.96:258:19
1413.96:258:19
1513.96:258:20
1613.96:268:21
1713.96:268:21
1813.96:268:22
1913.96:278:22
2013.96:278:23
2113.96:288:23
2213.96:288:24
2313.96:288:24
2413.96:298:25
2513.96:298:25
2613.96:308:25
2713.96:318:26
2813.96:318:26
2913.96:328:27
3013.96:328:27
3113.96:338:27

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 6.48 kWh/m² — the sunniest month for solar.

For context, solar energy here swings from a low near 2.37 kWh/m² to a high of 6.48 kWh/m² in December across the year — December's 6.48 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
16.4Intense
26.4Intense
36.4Intense
46.5Intense
56.5Intense
66.5Intense
76.5Intense
86.5Intense
96.5Intense
106.5Intense
116.5Intense
126.5Intense
136.5Intense
146.5Intense
156.5Intense
166.5Intense
176.5Intense
186.5Intense
196.5Intense
206.5Intense
216.5Intense
226.5Intense
236.5Intense
246.5Intense
256.4Intense
266.4Intense
276.4Intense
286.4Intense
296.4Intense
306.4Intense
316.4Intense
Planning a trip in December

Is December a good time to visit São Jerônimo?

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

5.2
Sightseeing
10th-best month of the year
6.7
Beach & pool
2nd-best month of the year

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

What to pack for São Jerônimo in December

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

In December, São Jerônimo sees daytime highs around 29°C and nights near 19°C. Pack light clothes and sun protection. Worth having: rain gear. About 12 days see rain.

light clothessun protectionrain gear

UV index in São Jerônimo 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 São Jerônimo peaks around January 15 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 19 at about 3 (moderate).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highModerateVery highExtremeJan 15UV 13Jun 19UV 3
UV index (midday)Level
Jan13Extreme
Feb12Extreme
Mar9Very high
Apr7Very high
May4Moderate
Jun3Moderate
Jul4Moderate
Aug5Moderate
Sep8Very high
Oct7Very high
Nov11Extreme
Dec12Extreme

Air quality in São Jerônimo 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 São Jerônimo is worst in August — around 20 µg/m³ PM2.5 (moderate), about 2.0× the cleanest month (December, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodAug 1720 µg/m³Dec 1811 µg/m³
PM2.5 (µg/m³)Level
Jan12Good
Feb11Good
Mar12Good
Apr15Moderate
May17Moderate
Jun17Moderate
Jul19Moderate
Aug20Moderate
Sep19Moderate
Oct13Moderate
Nov12Good
Dec10Good
Location & terrain

Where is São Jerônimo?

São Jerônimo sits at 30.0°S, 51.7°W, 18 m above sea level, in Brazil. The nearest listed city is Triunfo, 2.0 km away.

Topography around São Jerônimo

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

Within 3 km, the terrain around São Jerônimo has only modest variations in elevation — a maximum elevation change of 46 m around an average of 13 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 168 m; within 80 km, large variations in elevation — a maximum elevation change of 740 m.

The land around São Jerônimo is covered by trees (38%) and water (21%) within 3 km, trees (40%), grassland (30%) and cropland (20%) within 16 km, and trees (53%) within 80 km.

3 km
46 m
16 km
168 m
80 km
740 m
treesgrasslandcroplandartificial surfaceswaterwetland
December weather nearby: Triunfo 2.0 km · Charqueadas 9.0 km · Eldorado do Sul 17 km · Taquari 22 km · Butiá 29 km · Montenegro 39 km · Guaíba 42 km · Nova Santa Rita 45 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 São Jerônimo (-29.9592°, -51.7222°, elevation 18 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).