Grajaú weather in January

In January, Grajaú sees average daytime highs of 31°C and overnight lows near 23°C, with 172 mm of rain across 24.8 wet days and about 12.3 hours of daylight. It is the 10th-warmest and 3rd-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 3% of the time in January, and the air most often feels oppressive.

Daylight stretches from about 12 h 18 min at the start of January to 12 h 18 min by month's end. Set against the rest of the year, January is Grajaú's 10th-clearest and 9th-windiest month. For the whole year in context, see Grajaú's year-round climate.

Daytime high
31°
10th warmest
Overnight low
23°
8th coldest
Rainfall
172 mm
24.8 wet days
Daylight
12 h 18 min
6:05 AM – 6:23 PM
Cloud cover
82%
10th clearest
Wind
6 km/h
9th windiest
Solar energy
4.62 kWh/m²
Travel score
3.0
out of 10

Temperature in January

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 31°C through the month.

A typical January day in Grajaú reaches about 31°C in the afternoon and slips back to 23°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 28°C and 33°C. Set against its neighbours, January runs about 1°C cooler than December and on par with February.

20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
13123
23123
33123
43123
53123
63123
73123
83123
93123
103123
113123
123123
133123
143123
153123
163123
173122
183122
193122
203122
213123
223123
233123
243123
253123
263123
273123
283123
293123
303123
313123

How January really feels in Grajaú

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.

Grajaú weather by month

How January compares with the rest of the year at a glance. January is the 10th-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan31° / 23°17224.812.33.0
Feb30° / 22°17523.912.22.9
Mar31° / 23°18826.1122.9
Apr31° / 23°13220.411.93.3
May31° / 22°6410.511.74.2
Jun32° / 22°81.611.74.8
Jul33° / 21°50.811.74.4
Aug34° / 22°20.311.83.8
Sep35° / 23°91.7123.4
Oct34° / 24°325.312.13.4
Nov33° / 24°7811.912.33.4
Dec32° / 23°13517.712.33.3

Cloud cover in January

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 3% of the time in January.

Beyond those clear spells, partly cloudy skies cover about 9% of January, with mostly cloudy or overcast conditions the remaining 88%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
11783
21684
31585
41585
51486
61486
71387
81288
91189
101189
111189
121189
131090
141090
151090
161090
171090
181090
191189
201189
211189
221288
231288
241288
251288
261288
271387
281387
291387
301387
311387

Chance of precipitation in January

Any precipitation

Grajaú gets around 172 mm of rain over 24.8 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 80% and peaks near 82% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%151015202531
Rain chance (%)
173
274
375
476
577
677
778
879
979
1080
1180
1281
1381
1482
1582
1682
1782
1882
1982
2082
2182
2282
2382
2482
2582
2682
2782
2882
2982
3082
3182

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 97% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202531
Muggy (%)Oppressive (%)Miserable (%)
11972
21972
30982
40982
50982
60982
70982
80982
90982
100982
110982
120982
130982
140982
150982
160982
170982
180982
190973
200973
210973
220973
230973
240973
250973
260964
270964
280964
290964
300955
310955

Wind in January

Winds average 6 km/h in January.

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

0246810151015202531
Wind speed (km/h)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm
316calm

Sunrise & sunset in January

DaylightNight

Daylight runs from about 12 h 18 min at the start of January to 12 h 18 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 0 minutes over January. Sunrise moves from 5:58 AM to 6:10 AM, and sunset from 6:18 PM to 6:26 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.35:586:18
212.35:586:18
312.35:596:18
412.35:596:19
512.36:006:19
612.36:006:20
712.36:016:20
812.36:016:20
912.36:026:21
1012.36:026:21
1112.36:036:21
1212.36:036:22
1312.36:036:22
1412.36:046:22
1512.36:046:23
1612.36:056:23
1712.36:056:23
1812.36:066:23
1912.36:066:24
2012.36:066:24
2112.36:076:24
2212.36:076:24
2312.36:086:25
2412.36:086:25
2512.36:086:25
2612.36:096:25
2712.36:096:25
2812.36:096:25
2912.36:106:25
3012.36:106:25
3112.36:106:26

Solar energy in January

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in January, about 4.62 kWh/m².

For context, solar energy here swings from a low near 4.51 kWh/m² to a high of 6.39 kWh/m² in September across the year — January's 4.62 kWh/m² falls in the middle.

024151015202531
Solar energy (kWh/m²)Level
14.8Bright
24.7Bright
34.7Bright
44.7Bright
54.7Bright
64.7Bright
74.7Bright
84.7Bright
94.7Bright
104.6Bright
114.6Bright
124.6Bright
134.6Bright
144.6Bright
154.6Bright
164.6Bright
174.6Bright
184.6Bright
194.6Bright
204.6Bright
214.6Bright
224.6Bright
234.6Bright
244.6Bright
254.6Bright
264.6Bright
274.6Bright
284.6Bright
294.6Bright
304.7Bright
314.7Bright
Planning a trip in January

Hazard calendar for Grajaú

In seasonPeak

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

Grajaú's monsoon runs December–April, when most of the year's rain falls.

Monsoon
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is January a good time to visit Grajaú?

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

3.0
Sightseeing
10th-best month of the year
4.3
Beach & pool
10th-best month of the year

January is a weaker month for outdoor sightseeing in Grajaú.

What to pack for Grajaú in January

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

In January, Grajaú sees daytime highs around 31°C and nights near 23°C. Pack light clothes and rain gear. Worth having: sun protection. About 25 days see rain.

light clothesrain gearsun protection

UV index in Grajaú 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 Grajaú peaks around March 12 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 12 at about 10 (extreme).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeMar 12UV 15Jul 12UV 10
UV index (midday)Level
Jan14Extreme
Feb15Extreme
Mar15Extreme
Apr14Extreme
May11Extreme
Jun10Extreme
Jul10Very high
Aug11Extreme
Sep12Extreme
Oct12Extreme
Nov12Extreme
Dec10Extreme

Air quality in Grajaú 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 Grajaú is worst in October — around 28 µg/m³ PM2.5 (moderate), about 4.5× the cleanest month (June, 6 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateOct 1227 µg/m³Jun 176 µg/m³
PM2.5 (µg/m³)Level
Jan13Moderate
Feb12Good
Mar12Good
Apr11Good
May9Good
Jun6Good
Jul8Good
Aug17Moderate
Sep26Moderate
Oct28Moderate
Nov22Moderate
Dec17Moderate
Location & terrain

Where is Grajaú?

Grajaú sits at 5.8°S, 46.1°W, 163 m above sea level, in Brazil. The nearest listed city is Sítio Novo, 62 km away.

Topography around Grajaú

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

Within 3 km, the terrain around Grajaú has only modest variations in elevation — a maximum elevation change of 115 m around an average of 193 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 218 m; within 80 km, significant variations in elevation — a maximum elevation change of 593 m.

The land around Grajaú is covered by trees (53%), grassland (24%) and artificial surfaces (20%) within 3 km, trees (58%) and grassland (33%) within 16 km, and trees (66%) and grassland (26%) within 80 km.

3 km
115 m
16 km
218 m
80 km
593 m
treesshrubsgrasslandcroplandartificial surfaces
January weather nearby: Sítio Novo 62 km · Formosa da Serra Negra 70 km · Amarante do Maranhão 72 km · Jenipapo dos Vieiras 75 km · Arame 105 km · Barra do Corda 105 km · Governador Edison Lobão 136 km · João Lisboa 146 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 Grajaú (-5.8194°, -46.1386°, elevation 163 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).