Rio das Ostras weather in January

In January, Rio das Ostras sees average daytime highs of 30°C and overnight lows near 23°C, with 206 mm of rain across 16.6 wet days and about 13.2 hours of daylight. It is the 2nd-warmest and 2nd-wettest month of the year here.

Day-to-day highs hold fairly steady near 30°C through the month. The sky is clear or mostly clear about 23% of the time in January, and the air most often feels oppressive.

Daylight stretches from about 13 h 24 min at the start of January to 13 hours by month's end. Set against the rest of the year, January is Rio das Ostras's 10th-clearest and 6th-windiest month. For the whole year in context, see Rio das Ostras's year-round climate.

Daytime high
30°
2nd warmest
Overnight low
23°
11th coldest
Rainfall
206 mm
16.6 wet days
Daylight
13 h 12 min
6:20 AM – 7:34 PM
Cloud cover
68%
10th clearest
Wind
11 km/h
6th windiest
Solar energy
6.2 kWh/m²
Travel score
4.1
out of 10

Rio das Ostras is human settlement in Brazil.

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 30°C through the month.

A typical January day in Rio das Ostras reaches about 30°C in the afternoon and slips back to 23°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 26°C and 34°C. Set against its neighbours, January runs about 1°C warmer than December and on par with February.

20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
13023
23023
33023
43023
53023
63023
73023
83023
93023
103023
113023
123023
133023
143023
153023
163023
173023
183023
193023
203023
213023
223023
233024
243024
253024
263024
273024
283124
293124
303124
313124

How January really feels in Rio das Ostras

Once humidity and wind are folded in, January 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 January is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Rio das Ostras weather by month

How January compares with the rest of the year at a glance. January 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
Jan30° / 23°20616.613.24.1
Feb31° / 24°13612.712.84.2
Mar30° / 23°17217.812.24.3
Apr28° / 21°851211.55.7
May26° / 19°609.510.96.9
Jun26° / 18°315.910.67.6
Jul25° / 18°295.610.87.8
Aug26° / 18°346.311.27.6
Sep26° / 19°7310.111.96.7
Oct27° / 20°1081212.56.1
Nov27° / 21°20317.513.15.1
Dec29° / 23°2221913.44.2

Cloud cover in January

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 23% of the time in January.

Beyond those clear spells, partly cloudy skies cover about 14% of January, with mostly cloudy or overcast conditions the remaining 63%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13367
23367
33367
43466
53466
63466
73565
83565
93466
103565
113664
123763
133862
143862
153862
163763
173763
183763
193763
203763
213763
223763
233763
243763
253862
263961
274060
284060
294060
304159
314258

Chance of precipitation in January

Any precipitation

Rio das Ostras gets around 206 mm of rain over 16.6 wet days in January. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 53% and peaks near 60% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%151015202531
Rain chance (%)
160
259
358
458
557
656
756
855
954
1054
1153
1252
1352
1452
1552
1651
1751
1852
1952
2052
2151
2251
2351
2450
2550
2649
2749
2848
2948
3048
3148

Humidity in January

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, January lands in the oppressive band about 72% of days. Sticky, muggy-or-worse air turns up on roughly 99% of them.

0%25%50%75%100%151015202531
Humid (%)Muggy (%)Oppressive (%)Miserable (%)
11117117
21117117
31117117
41117117
51117117
61117117
71117117
81117117
91117117
101117117
111107217
121107217
131107217
141107217
151107217
161107217
171107217
181107217
191107118
201107118
211107118
221107118
231107019
241107019
251107019
26197119
27197119
28097219
29087319
30087319
31087319

Wind in January

Winds average 11 km/h in January.

Across January, daily wind ranges from about 10 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
110calm
210calm
310calm
410calm
510calm
610calm
710calm
810calm
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 January

DaylightNight

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

Days shrink by about 24 minutes over January. Sunrise moves from 6:10 AM to 6:30 AM, and sunset from 7:32 PM to 7:32 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.46:107:32
213.46:117:32
313.36:117:32
413.36:127:33
513.36:137:33
613.36:137:33
713.36:147:33
813.36:157:33
913.36:157:34
1013.36:167:34
1113.36:167:34
1213.36:177:34
1313.36:187:34
1413.36:187:34
1513.36:197:34
1613.26:207:34
1713.26:217:34
1813.26:217:34
1913.26:227:34
2013.26:237:34
2113.26:237:34
2213.26:247:34
2313.26:257:34
2413.16:257:34
2513.16:267:34
2613.16:277:33
2713.16:277:33
2813.16:287:33
2913.16:297:33
3013.16:297:33
3113.06:307:32

Solar energy in January

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in January, about 6.2 kWh/m².

For context, solar energy here swings from a low near 3.54 kWh/m² to a high of 6.31 kWh/m² in February across the year — January's 6.2 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
16.2Intense
26.2Intense
36.2Intense
46.2Intense
56.2Intense
66.2Intense
76.2Intense
86.2Intense
96.2Intense
106.2Intense
116.2Intense
126.2Intense
136.2Intense
146.2Intense
156.2Intense
166.2Intense
176.2Intense
186.2Intense
196.2Intense
206.3Intense
216.3Intense
226.3Intense
236.3Intense
246.3Intense
256.3Intense
266.3Intense
276.3Intense
286.3Intense
296.3Intense
306.3Intense
316.3Intense
Planning a trip in January

Hazard calendar for Rio das Ostras

In seasonPeak

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

Rio das Ostras'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 Rio das Ostras?

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

4.1
Sightseeing
12th-best month of the year
5.7
Beach & pool
10th-best month of the year

January is a reasonable time to visit Rio das Ostras for sightseeing.

What to pack for Rio das Ostras in January

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

In January, Rio das Ostras sees daytime highs around 30°C and nights near 23°C. Pack light clothes, rain gear and sun protection. About 17 days see rain.

light clothesrain gearsun protection

Sea temperature near Rio das Ostras in January

The nearest coast averages about 24°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 13 km away) is warmest in March at about 25°C and coldest in September near 21°C.

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

20°22°24°26°JanFebMarAprMayJunJulAugSepOctNovDeccoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan24Refreshing
Feb24Warm
Mar25Warm
Apr25Warm
May24Refreshing
Jun23Refreshing
Jul22Refreshing
Aug22Refreshing
Sep21Refreshing
Oct22Refreshing
Nov22Refreshing
Dec24Refreshing

UV index in Rio das Ostras in January

LowModerateHighVery highExtreme

Clear-sky midday UV in January 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 das Ostras peaks around January 16 at about 14 (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 highExtremeJan 16UV 14Jul 11UV 6
UV index (midday)Level
Jan14Extreme
Feb14Extreme
Mar13Extreme
Apr9Very high
May7High
Jun6High
Jul6High
Aug8Very high
Sep8Very high
Oct12Extreme
Nov14Extreme
Dec14Extreme
Location & terrain

Where is Rio das Ostras?

Rio das Ostras sits at 22.5°S, 41.9°W, 11 m above sea level, in Brazil. The nearest listed city is Macaé, 23 km away.

Topography around Rio das Ostras

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

Within 3 km, the terrain around Rio das Ostras has only modest variations in elevation — a maximum elevation change of 49 m around an average of 4 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 693 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,215 m.

The land around Rio das Ostras is covered by water (39%) and artificial surfaces (32%) within 3 km, water (45%) and grassland (27%) within 16 km, and water (37%), trees (31%) and grassland (28%) within 80 km.

3 km
49 m
16 km
693 m
80 km
2,215 m
treesgrasslandartificial surfacesbare terrainwaterwetlandmangroves
January weather nearby: Macaé 23 km · Buzios 25 km · Casimiro de Abreu 27 km · São Pedro da Aldeia 38 km · Cabo Frio 41 km · Iguaba Grande 45 km · Silva Jardim 48 km · Arraial do Cabo 50 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 das Ostras (-22.5269°, -41.945°, elevation 11 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).