Castro in Summer
In summer (December, January and February), Castro sees average daytime highs around 26°C and overnight lows near 17°C, with 585 mm of rain over about 65 wet days across the season. It is the warmest season of the year and the wettest season of the year.
Across summer, daytime highs hold fairly steady around 26°C. The sky is clear or mostly clear about 11% of the time across summer, and the air most often feels humid.
Summer is Castro's weakest season of the year to visit on our travel score. For the whole year in context, see Castro's year-round climate.
- Avg daytime high
- 26°C
- warmest season of the year
- Avg overnight low
- 17°C
- Rainfall
- 585 mm
- 65 wet days
- Avg wind
- 10 km/h
- Travel score
- 4.7
- weakest season of the year
- Months
- Dec · Jan · Feb
Temperature in Castro in Summer
Across summer, daytime highs hold fairly steady around 26°C.
A typical summer day in Castro reaches about 26°C and drops to 17°C overnight. The warmest of the three months is January, the coolest December.
Castro weather by month
How the three summer months (December, January and February) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 26° / 17° | 235 | 23.8 | 13.4 | 4.5 |
| Feb | 26° / 17° | 178 | 21 | 12.9 | 4.6 |
| Mar | 25° / 17° | 132 | 18 | 12.2 | 5.5 |
| Apr | 23° / 15° | 70 | 9.6 | 11.4 | 6.9 |
| May | 20° / 12° | 89 | 8.9 | 10.8 | 6.5 |
| Jun | 19° / 11° | 93 | 8.4 | 10.5 | 6.5 |
| Jul | 19° / 10° | 79 | 7 | 10.6 | 6.8 |
| Aug | 21° / 11° | 72 | 7.3 | 11.1 | 7.2 |
| Sep | 22° / 12° | 127 | 10.4 | 11.8 | 6.6 |
| Oct | 23° / 14° | 138 | 15.1 | 12.6 | 5.9 |
| Nov | 24° / 15° | 133 | 16.1 | 13.2 | 5.8 |
| Dec | 26° / 17° | 173 | 20.3 | 13.5 | 5.1 |
Cloud cover in Summer
The sky is clear or mostly clear about 11% of the time across summer.
Chance of precipitation in Summer
Castro gets around 585 mm of rain over 65 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels humid — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 10 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 13 h 24 min in early December to 12 h 36 min by late February. The lit band spans sunrise to sunset each day.
Solar energy in Summer
Average shortwave solar energy reaching the ground each day across summer, about 5.6 kWh/m².
Is summer a good time to visit Castro?
Our two travel scores rate summer for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
summer is a reasonable time to visit Castro for sightseeing.
What to pack for Castro in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Castro sees daytime highs around 26°C and nights near 17°C. Pack rain gear. Worth having: light clothes and sun protection. About 65 days see rain.
UV index in Castro in Summer
Clear-sky midday UV across summer averages around 15 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Castro peaks around January 19 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 13 at about 5 (high).
The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 15 | 15 | 12 | 9 | 7 | 6 | 5 | 7 | 5 | 11 | 14 | 14 |
| Level | Extreme | Extreme | Extreme | Very high | High | High | High | High | High | Extreme | Extreme | Extreme |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 15 | Extreme |
| Feb | 15 | Extreme |
| Mar | 12 | Extreme |
| Apr | 9 | Very high |
| May | 7 | High |
| Jun | 6 | High |
| Jul | 5 | High |
| Aug | 7 | High |
| Sep | 5 | High |
| Oct | 11 | Extreme |
| Nov | 14 | Extreme |
| Dec | 14 | Extreme |
Air quality in Castro in Summer
Average fine-particle pollution (PM2.5) through the year — so you can see where summer falls, not just the annual average.
Air quality in Castro is worst in September — around 17 µg/m³ PM2.5 (moderate), about 2.6× the cleanest month (March, 6 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 7 | 7 | 6 | 7 | 8 | 8 | 10 | 14 | 17 | 10 | 7 | 7 |
| Level | Good | Good | Good | Good | Good | Good | Good | Moderate | Moderate | Good | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 7 | Good |
| Feb | 7 | Good |
| Mar | 6 | Good |
| Apr | 7 | Good |
| May | 8 | Good |
| Jun | 8 | Good |
| Jul | 10 | Good |
| Aug | 14 | Moderate |
| Sep | 17 | Moderate |
| Oct | 10 | Good |
| Nov | 7 | Good |
| Dec | 7 | Good |
Where is Castro?
Castro sits at 24.8°S, 50.0°W, 986 m above sea level, in Brazil. The nearest listed city is Piraí do Sul, 30 km away.
Topography around Castro
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Castro.
Within 3 km, the terrain around Castro has only modest variations in elevation — a maximum elevation change of 151 m around an average of 1,004 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 304 m; within 80 km, large variations in elevation — a maximum elevation change of 1,128 m.
The land around Castro is covered by trees (42%), artificial surfaces (28%) and grassland (20%) within 3 km, trees (42%) and cropland (42%) within 16 km, and trees (58%) and cropland (30%) within 80 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
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 Castro (-24.7893°, -50.0123°, elevation 986 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.