Grajaú weather in May

In May, Grajaú sees average daytime highs of 31°C and overnight lows near 22°C, with 64 mm of rain across 10.5 wet days and about 11.7 hours of daylight. It is the 8th-warmest and 7th-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 25% of the time in May, and the air most often feels oppressive.

Daylight stretches from about 11 h 48 min at the start of May to 11 h 42 min by month's end. Set against the rest of the year, May is Grajaú's 6th-clearest and 6th-windiest month. For the whole year in context, see Grajaú's year-round climate.

Daytime high
31°
8th warmest
Overnight low
22°
4th coldest
Rainfall
64 mm
10.5 wet days
Daylight
11 h 42 min
6:09 AM – 5:53 PM
Cloud cover
62%
6th clearest
Wind
7 km/h
6th windiest
Solar energy
4.82 kWh/m²
Travel score
4.2
out of 10

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

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

A typical May day in Grajaú reaches about 31°C in the afternoon and slips back to 22°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 30°C and 33°C. Set against its neighbours, May runs on par with April and about 1°C cooler than June.

20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
13122
23122
33122
43122
53122
63122
73122
83122
93122
103122
113122
123122
133122
143122
153122
163122
173122
183122
193122
203122
213122
223222
233222
243222
253222
263222
273222
283222
293222
303222
313222

How May really feels in Grajaú

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

Grajaú weather by month

How May compares with the rest of the year at a glance. May is the 8th-warmest and 7th-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 May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 25% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 23% of May, with mostly cloudy or overcast conditions the remaining 52%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13169
23169
33268
43367
53466
63664
73763
84060
94159
104258
114357
124555
134654
144753
154852
164951
175050
185050
195149
205248
215446
225446
235545
245743
255941
266040
276139
286337
296436
306634
316733

Chance of precipitation in May

Any precipitation

Grajaú gets around 64 mm of rain over 10.5 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 34% and peaks near 55% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%151015202531
Rain chance (%)
155
253
352
450
548
646
744
842
939
1037
1135
1234
1332
1431
1531
1630
1730
1829
1929
2028
2128
2228
2327
2426
2526
2625
2724
2822
2921
3020
3118

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, May lands in the oppressive band about 85% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202531
Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1018811
2018811
3018910
4028810
502899
602899
702899
802899
903898
1003898
1103898
1203898
1304888
1404888
1505878
1605887
1706877
1806886
1907876
2008866
2109865
22010855
23012835
24013834
25015814
26017794
27019783
28021763
29023743
30125713
31128692

Wind in May

Winds average 7 km/h in May.

Across May, daily wind ranges from about 6 km/h on the calmest days to 8 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
16calm
26calm
36calm
46calm
56calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
298calm
308calm
318calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 11 h 48 min at the start of May to 11 h 42 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 6 minutes over May. Sunrise moves from 6:08 AM to 6:11 AM, and sunset from 5:56 PM to 5:53 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.86:085:56
211.86:085:55
311.86:085:55
411.86:085:55
511.86:085:55
611.86:085:54
711.86:085:54
811.86:085:54
911.86:085:54
1011.86:085:54
1111.86:085:54
1211.86:085:53
1311.76:085:53
1411.76:085:53
1511.76:095:53
1611.76:095:53
1711.76:095:53
1811.76:095:53
1911.76:095:53
2011.76:095:53
2111.76:095:53
2211.76:105:52
2311.76:105:52
2411.76:105:52
2511.76:105:52
2611.76:105:52
2711.76:105:52
2811.76:115:52
2911.76:115:53
3011.76:115:53
3111.76:115:53

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 4.82 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 — May's 4.82 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
14.7Bright
24.7Bright
34.7Bright
44.7Bright
54.7Bright
64.7Bright
74.8Bright
84.8Bright
94.8Bright
104.8Bright
114.8Bright
124.8Bright
134.8Bright
144.8Bright
154.8Bright
164.8Bright
174.8Bright
184.8Bright
194.8Bright
204.9Bright
214.9Bright
224.9Bright
234.9Bright
244.9Bright
254.9Bright
264.9Bright
274.9Bright
285.0Bright
295.0Bright
305.0Bright
315.0Bright
Planning a trip in May

Hazard calendar for Grajaú

In seasonPeak

None of Grajaú's seasonal hazards are active in May. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

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 May a good time to visit Grajaú?

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

4.2
Sightseeing
3rd-best month of the year
6.4
Beach & pool
6th-best month of the year

May is a reasonable time to visit Grajaú for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Grajaú in May

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

In May, Grajaú sees daytime highs around 31°C and nights near 22°C. Pack light clothes. Worth having: rain gear and sun protection. About 11 days see rain.

light clothesrain gearsun protection

UV index in Grajaú in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 11 (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 May

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where May 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
May 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).