Climate Overview
The climate in Castanhal is hot. The average annual temperature is 27°C and approximately 2522mm of precipitation falls per year. Castanhal receives a notable amount of rainfall throughout the year, including during its driest month. Castanhal sits near the equator, so seasonal temperature differences are minimal throughout the year.
Temperature
Castanhal sees moderate temperature variation throughout the year, ranging from 23°C to 34°C. The warmest month is October, when average highs reach 34°C and the mean temperature sits around 28°C. July is the coolest month, with minimum temperatures around 23°C and an average of 27°C. On average, daily temperatures fluctuate by about 9°C between overnight lows and afternoon highs.
Precipitation
Castanhal is a very wet location, receiving approximately 2522mm of precipitation annually, which averages out to around 210mm per month. The wettest month is March, averaging 560mm of rainfall. April and February also tend to see above-average precipitation. The driest month is September, with just 33mm. That's 527mm less than March, the wettest month. Rainfall is heavily concentrated in certain months, creating a distinct wet and dry season. Visitors should plan around these patterns, as the difference between peak and low months is dramatic.
Wind
Castanhal is mildly breezy, with an average annual wind speed of 13km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is October, averaging 15km/h, though still comfortable for most outdoor activities. The calmest conditions occur in April, with average winds dropping to 11km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 4km/h between the calmest and windiest months.
Seasons
89 days until Winter
It is currently autumn in Castanhal, which began on March 20, 2026. Castanhal sits near the equator, so the traditional four-season cycle is less pronounced — temperatures remain relatively stable year-round. The warmest period peaks in October at around 34°C, while the coldest stretch bottoms out in July near 23°C. Winter is next, beginning on June 21, 2026 — 89 days from now.
Spring
Temperatures range from 23 to 34°C. Rainfall is relatively light, with around 140mm over the season and a monthly average of 47mm. Winds are generally light, averaging 15km/h. Light layers work well as temperatures warm through the season — a great time to be outdoors.
Summer
Temperatures range from 23 to 32°C. Rainfall is heavy, totalling around 862mm across the season with a monthly average of 287mm. Winds are generally light, averaging 13km/h. Light, breathable clothing is ideal — perfect conditions for outdoor activities.
Autumn
Temperatures range from 23 to 31°C. Rainfall is heavy, totalling around 1308mm across the season with a monthly average of 436mm. Winds are generally light, averaging 11km/h. A waterproof jacket and sturdy footwear are recommended as rain becomes more frequent.
Winter
Temperatures range from 23 to 33°C. Precipitation is moderate at around 212mm for the season, averaging 71mm per month. Winds are generally light, averaging 12km/h. A light jacket or sweater is usually sufficient, though cooler evenings may call for an extra layer.
Monthly Climate Data
The table below shows monthly climate averages for Castanhal based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.
