Castelo do Piauí weather in May

In May, Castelo do Piauí sees average daytime highs of 32°C and overnight lows near 23°C, with 76 mm of rain across 8.8 wet days and about 11.8 hours of daylight. It is the 9th-warmest and 5th-wettest month of the year here.

Day-to-day highs hold fairly steady near 32°C through the month. The sky is clear or mostly clear about 28% 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 Castelo do Piauí's 8th-clearest and 8th-windiest month. For the whole year in context, see Castelo do Piauí's year-round climate.

Daytime high
32°
9th warmest
Overnight low
23°
6th coldest
Rainfall
76 mm
8.8 wet days
Daylight
11 h 48 min
5:50 AM – 5:35 PM
Cloud cover
59%
8th clearest
Wind
9 km/h
8th windiest
Solar energy
5.04 kWh/m²
Travel score
3.9
out of 10

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 32°C through the month.

A typical May day in Castelo do Piauí reaches about 32°C in the afternoon and slips back to 23°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 35°C. Set against its neighbours, May runs about 1°C warmer than April and on par with June.

20°25°30°35°40°151015202531
Avg high (°C)Avg low (°C)
13223
23223
33223
43223
53223
63223
73223
83223
93223
103223
113223
123223
133223
143223
153223
163223
173223
183323
193323
203323
213323
223323
233323
243323
253323
263323
273323
283323
293323
303323
313323

How May really feels in Castelo do Piauí

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.

Castelo do Piauí weather by month

How May compares with the rest of the year at a glance. May is the 9th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan33° / 24°15616.512.32.8
Feb32° / 23°17917.112.22.9
Mar32° / 23°25721.8122.9
Apr32° / 23°18418.311.93.3
May32° / 23°768.811.83.9
Jun33° / 23°11211.74.2
Jul34° / 23°61.111.74.0
Aug35° / 24°10.111.83.3
Sep36° / 24°10.3122.5
Oct37° / 25°140.812.12.0
Nov37° / 25°142.612.22.1
Dec36° / 25°416.712.32.4

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 28% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 26% of May, with mostly cloudy or overcast conditions the remaining 46%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13862
23961
34060
44060
54258
64357
74456
84654
94852
104852
115050
125149
135248
145347
155347
165545
175644
185743
195842
205941
215941
226139
236139
246238
256337
266337
276436
286634
296634
306733
316733

Chance of precipitation in May

Any precipitation

Castelo do Piauí gets around 76 mm of rain over 8.8 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 29% and peaks near 52% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%151015202531
Rain chance (%)
152
250
348
446
544
642
740
837
935
1033
1131
1229
1328
1426
1525
1625
1724
1824
1923
2023
2122
2221
2321
2420
2520
2619
2719
2818
2917
3016
3115

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 51% of days. Sticky, muggy-or-worse air turns up on roughly 92% of them.

0%25%50%75%100%151015202531
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1031879
2031978
3032077
4032176
5042274
6142471
7142669
8152767
9152965
10163063
11163261
12173458
13173557
14173755
15183952
16184150
17084349
18084547
19094645
20094843
21095041
22095239
23095437
240105535
250105733
261115731
271125829
281135927
291146025
301156123
311166221

Wind in May

Winds average 9 km/h in May.

Across May, daily wind ranges from about 8 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
18calm
28calm
38calm
48calm
58calm
68calm
79calm
89calm
99calm
109calm
119calm
129calm
139calm
149calm
159calm
169calm
1710calm
1810calm
1910calm
2010calm
2110calm
2210calm
2310calm
2410calm
2510calm
2610calm
2710calm
2811calm
2911calm
3011calm
3111calm

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 5:49 AM to 5:52 AM, and sunset from 5:38 PM to 5:35 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.85:495:38
211.85:495:38
311.85:495:37
411.85:495:37
511.85:495:37
611.85:495:37
711.85:495:37
811.85:495:36
911.85:495:36
1011.85:495:36
1111.85:495:36
1211.85:495:36
1311.85:495:36
1411.85:495:35
1511.85:505:35
1611.85:505:35
1711.85:505:35
1811.85:505:35
1911.75:505:35
2011.75:505:35
2111.75:505:35
2211.75:505:35
2311.75:515:35
2411.75:515:35
2511.75:515:35
2611.75:515:35
2711.75:515:35
2811.75:525:35
2911.75:525:35
3011.75:525:35
3111.75:525:35

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.04 kWh/m².

For context, solar energy here swings from a low near 4.99 kWh/m² to a high of 6.94 kWh/m² in October across the year — May's 5.04 kWh/m² sits near the bottom.

0246151015202531
Solar energy (kWh/m²)Level
14.9Bright
24.9Bright
34.9Bright
45.0Bright
55.0Bright
65.0Bright
75.0Bright
85.0Bright
95.0Bright
105.0Bright
115.0Bright
125.0Bright
135.0Bright
145.1Bright
155.1Bright
165.1Bright
175.1Bright
185.1Bright
195.1Bright
205.1Bright
215.1Bright
225.1Bright
235.1Bright
245.1Bright
255.1Bright
265.1Bright
275.1Bright
285.1Bright
295.1Bright
305.1Bright
315.1Bright
Planning a trip in May

Hazard calendar for Castelo do Piauí

In seasonPeak

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

Castelo do Piauí's monsoon runs January–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 Castelo do Piauí?

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

3.9
Sightseeing
3rd-best month of the year
6.5
Beach & pool
4th-best month of the year

May is a weaker month for outdoor sightseeing in Castelo do Piauí. The water and warmth also suit a beach or pool day.

What to pack for Castelo do Piauí in May

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

In May, Castelo do Piauí sees daytime highs around 32°C and nights near 23°C. Pack light clothes. Worth having: rain gear and sun protection. About 9 days see rain.

light clothesrain gearsun protection

UV index in Castelo do Piauí 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 Castelo do Piauí peaks around March 15 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 24 at about 10 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeExtremeMar 15UV 15Jul 24UV 10
UV index (midday)Level
Jan13Extreme
Feb14Extreme
Mar15Extreme
Apr14Extreme
May11Extreme
Jun10Extreme
Jul10Very high
Aug10Very high
Sep12Extreme
Oct12Extreme
Nov12Extreme
Dec11Extreme
Location & terrain

Where is Castelo do Piauí?

Castelo do Piauí sits at 5.3°S, 41.6°W, 241 m above sea level, in Brazil. The nearest listed city is São Miguel do Tapuio, 32 km away.

Topography around Castelo do Piauí

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

Within 3 km, the terrain around Castelo do Piauí has only modest variations in elevation — a maximum elevation change of 82 m around an average of 249 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 300 m; within 80 km, large variations in elevation — a maximum elevation change of 790 m.

The land around Castelo do Piauí is covered by shrubs (67%) within 3 km, shrubs (63%) and trees (31%) within 16 km, and shrubs (65%) and trees (27%) within 80 km.

3 km
82 m
16 km
300 m
80 km
790 m
treesshrubsgrasslandcroplandartificial surfaces
May weather nearby: São Miguel do Tapuio 32 km · Campo Maior 88 km · Novo Oriente 89 km · Crateús 99 km · Pedro II 100 km · Altos 105 km · Quiterianópolis 111 km · Piripiri 119 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 Castelo do Piauí (-5.3222°, -41.5525°, elevation 241 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).