Jacareí weather in January

In January, Jacareí sees average daytime highs of 28°C and overnight lows near 20°C, with 226 mm of rain across 22.1 wet days and about 13.3 hours of daylight. It is the 2nd-warmest and 1st-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 13% of the time in January, and the air most often feels muggy.

Daylight stretches from about 13 h 24 min at the start of January to 13 h 06 min by month's end. Set against the rest of the year, January is Jacareí's 12th-clearest and 10th-windiest month. For the whole year in context, see Jacareí's year-round climate.

Daytime high
28°
2nd warmest
Overnight low
20°
12th coldest
Rainfall
226 mm
22.1 wet days
Daylight
13 h 18 min
6:34 AM – 7:52 PM
Cloud cover
76%
12th clearest
Wind
7 km/h
10th windiest
Solar energy
5.26 kWh/m²
Travel score
4.4
out of 10

Jacareí is human settlement in Brazil.

Air quality
Good
PM10 24 µg/m³ · 2016

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in January

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 28°C through the month.

A typical January day in Jacareí reaches about 28°C in the afternoon and slips back to 20°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 24°C and 32°C. Set against its neighbours, January runs on par with December and on par with February.

15°20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
12819
22819
32819
42819
52819
62819
72819
82820
92820
102820
112820
122820
132820
142820
152820
162820
172820
182820
192820
202820
212820
222820
232820
242820
252820
262820
272820
282820
292820
302820
312820

Jacareí weather by month

How January compares with the rest of the year at a glance. January is the 2nd-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan28° / 20°22622.113.34.4
Feb28° / 20°17118.512.84.3
Mar28° / 19°13918.112.25.2
Apr26° / 17°579.511.56.7
May24° / 15°577.610.97.3
Jun23° / 13°385.110.67.8
Jul23° / 12°445.110.77.8
Aug24° / 13°355.211.27.9
Sep25° / 15°769.911.96.8
Oct26° / 17°10913.612.55.9
Nov27° / 18°14216.613.15.4
Dec28° / 19°17220.113.44.8

Cloud cover in January

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 13% of the time in January, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 12% of January, with mostly cloudy or overcast conditions the remaining 75%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
12575
22476
32377
42377
52377
62476
72476
82476
92476
102476
112575
122575
132575
142674
152674
162575
172575
182575
192575
202575
212476
222575
232575
242575
252575
262674
272674
282773
292872
302971
312971

Chance of precipitation in January

Any precipitation

Jacareí gets around 226 mm of rain over 22.1 wet days in January, the wettest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 70% and peaks near 72% on the wettest days.

0%20%40%60%80%151015202531
Rain chance (%)
169
269
369
470
570
671
771
872
972
1072
1171
1271
1371
1471
1570
1670
1770
1870
1970
2070
2170
2270
2370
2470
2570
2670
2770
2870
2970
3070
3170

Humidity in January

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, January lands in the muggy band about 77% of days. Sticky, muggy-or-worse air turns up on roughly 83% of them.

0%25%50%75%100%151015202531
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1119755
2119746
3118756
4118756
5118756
6017767
7017767
8016777
9016777
10116767
11115786
12115786
13115786
14115786
15115786
16116776
17116776
18116776
19116776
20116785
21116785
22116785
23216775
24216766
25216766
26216766
27216766
28216766
29216766
30216757
31216757

Wind in January

Winds average 7 km/h in January.

Across January, daily wind ranges from about 6 km/h on the calmest days to 7 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
126calm
136calm
146calm
156calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
266calm
276calm
286calm
296calm
306calm
316calm

Sunrise & sunset in January

DaylightNight

Daylight runs from about 13 h 24 min at the start of January to 13 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 18 minutes over January. Sunrise moves from 6:25 AM to 6:45 AM, and sunset from 7:49 PM to 7:50 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.46:257:49
213.46:257:50
313.46:267:50
413.46:277:50
513.46:277:50
613.46:287:51
713.46:287:51
813.46:297:51
913.46:307:51
1013.36:307:51
1113.36:317:52
1213.36:327:52
1313.36:327:52
1413.36:337:52
1513.36:347:52
1613.36:347:52
1713.36:357:52
1813.36:367:52
1913.36:377:52
2013.26:377:52
2113.26:387:52
2213.26:397:52
2313.26:397:51
2413.26:407:51
2513.26:417:51
2613.26:417:51
2713.16:427:51
2813.16:437:50
2913.16:437:50
3013.16:447:50
3113.16:457:50

Solar energy in January

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in January, about 5.26 kWh/m².

For context, solar energy here swings from a low near 3.39 kWh/m² to a high of 5.52 kWh/m² in December across the year — January's 5.26 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.4Bright
25.4Bright
35.4Bright
45.3Bright
55.3Bright
65.3Bright
75.3Bright
85.3Bright
95.3Bright
105.3Bright
115.3Bright
125.3Bright
135.3Bright
145.3Bright
155.3Bright
165.3Bright
175.3Bright
185.3Bright
195.3Bright
205.3Bright
215.3Bright
225.3Bright
235.3Bright
245.3Bright
255.3Bright
265.3Bright
275.3Bright
285.4Bright
295.4Bright
305.4Bright
315.4Bright
Planning a trip in January

Hazard calendar for Jacareí

In seasonPeak

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

Jacareí'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 January a good time to visit Jacareí?

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

4.4
Sightseeing
11th-best month of the year
4.9
Beach & pool
12th-best month of the year

January is a reasonable time to visit Jacareí for sightseeing.

What to pack for Jacareí in January

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

In January, Jacareí sees daytime highs around 28°C and nights near 20°C. Pack light clothes and rain gear. Worth having: sun protection. About 22 days see rain.

light clothesrain gearsun protection

Sea temperature near Jacareí in January

The nearest coast averages about 27°C in January — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 64 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°25°JanFebMarAprMayJunJulAugSepOctNovDeccoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan27Warm
Feb27Warm
Mar27Warm
Apr26Warm
May24Refreshing
Jun22Refreshing
Jul21Refreshing
Aug21Refreshing
Sep21Refreshing
Oct22Refreshing
Nov23Refreshing
Dec25Warm

UV index in Jacareí in January

LowModerateHighVery highExtreme

Clear-sky midday UV in January peaks around 15 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Jacareí peaks around February 8 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 11 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 highExtremeFeb 8UV 15Jul 11UV 6
UV index (midday)Level
Jan15Extreme
Feb15Extreme
Mar12Extreme
Apr9Very high
May7High
Jun6High
Jul6High
Aug8Very high
Sep8Very high
Oct11Extreme
Nov13Extreme
Dec14Extreme

Air quality in Jacareí in January

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where January falls, not just the annual average.

Air quality in Jacareí is worst in June — around 32 µg/m³ PM2.5 (moderate), about 2.0× the cleanest month (November, 16 µg/m³).

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

010203040JanFebMarAprMayJunJulAugSepOctNovDecModerateJun 2132 µg/m³Nov 2316 µg/m³
PM2.5 (µg/m³)Level
Jan16Moderate
Feb17Moderate
Mar19Moderate
Apr21Moderate
May27Moderate
Jun32Moderate
Jul31Moderate
Aug28Moderate
Sep28Moderate
Oct20Moderate
Nov16Moderate
Dec16Moderate
Location & terrain

Where is Jacareí?

Jacareí sits at 23.3°S, 46.0°W, 574 m above sea level, in Brazil. The nearest listed city is Guararema, 14 km away.

Topography around Jacareí

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

Within 3 km, the terrain around Jacareí has only modest variations in elevation — a maximum elevation change of 129 m around an average of 589 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 295 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,071 m.

The land around Jacareí is covered by artificial surfaces (54%), trees (21%) and grassland (20%) within 3 km, grassland (44%) and trees (37%) within 16 km, and trees (52%) and grassland (26%) within 80 km.

3 km
129 m
16 km
295 m
80 km
2,071 m
treesgrasslandcroplandartificial surfaceswater
January weather nearby: Guararema 14 km · São José dos Campos 16 km · Santa Isabel 26 km · Salesópolis 28 km · Biritiba Mirim 31 km · Paraibuna 32 km · Mogi das Cruzes 33 km · Caçapava 35 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 Jacareí (-23.3053°, -45.9658°, elevation 574 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).