Castelo do Piauí climate — normals and trends
Castelo do Piauí (Brazil) has a tropical savanna climate (Aw) under the Köppen-Geiger classification. Its mean annual temperature is 28.2 °C and it receives 984 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is October (30.5 °C on average) and the coldest is March (26.1 °C). Rainfall peaks in March.
Castelo do Piauí averages 0 frost days, 319 hot days (≥ 30 °C) and 100 rainy days per year.
Castelo do Piauí has warmed by +1.1 °C between 1940 and 2025, or +0.13 °C per decade. This trend is statistically significant.
The hottest day of the period reached 39.9 °C (on 31 October 2012) and the coldest 18.3 °C (on 16 May 1959).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
Castelo do PiauíPiauí
- coords
- -5.32°, -41.55°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
28.2°C
Average daily high
33.4°C
Average daily low
23.4°C
Annual rainfall
984mm
Sunshine / day
11.0h
Mean relative humidity
59%
Average peak wind
17.7km/h
Seasonal range
4.4°C
Frost days (< 0 °C)
0 d/yr
Hot days (≥ 30 °C)
319 d/yr
Rainy days (≥ 1 mm)
100 d/yr
Annual snowfall
0.0 cm
Average feels-like high
35.6 °C
Average feels-like low
25.3 °C
Average peak gust
37.7 km/h
Tropical nights (≥ 20 °C)
364 d/yr
Solar radiation
21.0 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.1 °C
since 1940
+0.1 °C per decade · r² = 0.16 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
39.9 °C
31 October 2012
Coldest day
18.3 °C
16 May 1959
Wettest day
205 mm
1 March 1988
Windiest day
33.5 km/h
21 June 2020
Strongest gust
63.4 km/h
4 October 1958
Hottest feels-like
43.1 °C
11 March 2010
Coldest feels-like
17.5 °C
4 July 1974
Sunniest day
12.3 h
18 November 1940
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 32.8 °C | +0.1 °C | 145 mm | -6 mm |
| Feb | 32.3 °C | +0.7 °C | 120 mm | -73 mm |
| Mar | 31.1 °C | +0.3 °C | 108 mm | -172 mm |
| Apr | 32.4 °C | +1.7 °C | 43 mm | -154 mm |
| May | 33.4 °C | +1.8 °C | 6 mm | -64 mm |
| Jun | 33.5 °C | +0.9 °C | 1 mm | -10 mm |
| Jul | 34.7 °C | +1.3 °C | 0 mm | -5 mm |
| Aug | 35.7 °C | +1.1 °C | 1 mm | +0 mm |
| Sep | 36.6 °C | +0.8 °C | 0 mm | -2 mm |
| Oct | 37.2 °C | +0.8 °C | 2 mm | -6 mm |
| Nov | 37.0 °C | +1.0 °C | 1 mm | -14 mm |
| Dec | 35.0 °C | 0.0 °C | 21 mm | -33 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Castelo do Piauí?
Castelo do Piauí has a tropical savanna climate (Köppen Aw). Over 1940-2025, the average annual temperature is 28.2 °C and it receives 984 mm of precipitation per year.
What is the hottest day ever recorded in Castelo do Piauí?
The hottest day measured in Castelo do Piauí between 1940 and 2025 was 31 October 2012, reaching 39.9 °C.
What is the coldest day in Castelo do Piauí?
The coldest day measured in Castelo do Piauí between 1940 and 2025 was 16 May 1959, at 18.3 °C.
Does it snow in Castelo do Piauí?
Almost never: Castelo do Piauí sees virtually no snow, with about 0 frost days per year.
Has the climate of Castelo do Piauí warmed?
Yes: Castelo do Piauí warmed by +1.1 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Castelo do Piauí?
The wettest day measured in Castelo do Piauí between 1940 and 2025 was 1 March 1988, with 205 mm of rain in 24 hours.
What was the windiest day in Castelo do Piauí?
The windiest day measured in Castelo do Piauí between 1940 and 2025 was 21 June 2020, with winds reaching 33.5 km/h.
What is the warmest month in Castelo do Piauí?
The warmest month in Castelo do Piauí is October (30.5 °C on average); the coldest is March (26.1 °C).
How much does it rain in Castelo do Piauí?
Castelo do Piauí receives on average 984 mm of precipitation per year, spread over about 100 rainy days.
Is it sunny in Castelo do Piauí?
Castelo do Piauí gets on average 11.0 hours of sunshine per day, roughly 4,015 hours per year over 1940-2025.
Are there tropical nights in Castelo do Piauí?
Yes: Castelo do Piauí has on average 364 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Castelo do Piauí?
In Castelo do Piauí, between 1940 and 2025, the highest apparent temperature reached 43.1 °C on 11 March 2010, and the lowest was 17.5 °C on 4 July 1974.
Compare Castelo do Piauí with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Castelo do Piauí