Climate Overview
The climate in São Luís is hot. The average annual temperature is 27°C and approximately 1924mm of precipitation falls per year. March is the wettest month, receiving around 431mm of rainfall. São Luís sits near the equator, so seasonal temperature differences are minimal throughout the year.
Temperature
São Luís has relatively stable temperatures year-round, staying within a 6°C range. The warmest month is October, when average highs reach 31°C and the mean temperature sits around 28°C. March is the coolest month, with minimum temperatures around 25°C and an average of 26°C. Daily temperature variation is modest, with an average difference of 5°C between highs and lows.
Precipitation
São Luís is a fairly wet location, receiving approximately 1924mm of precipitation annually, which averages out to around 160mm per month. The wettest month is March, averaging 431mm of rainfall. April and February also tend to see above-average precipitation. The driest month is September, with just 10mm. That's 420mm 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
São Luís is mildly breezy, with an average annual wind speed of 17km/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 22km/h, noticeable enough to affect lighter outdoor activities. The calmest conditions occur in April, with average winds dropping to 14km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 8km/h gap between the calmest and windiest months.
Seasons
90 days until Winter
It is currently autumn in São Luís, which began on March 20, 2026. São Luís 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 31°C, while the coldest stretch bottoms out in March near 25°C. Winter is next, beginning on June 21, 2026 — 90 days from now.
Spring
Temperatures range from 26 to 31°C. Rainfall is relatively light, with around 58mm over the season and a monthly average of 19mm. Winds are moderate at around 22km/h. Light layers work well as temperatures warm through the season — a great time to be outdoors.
Summer
Temperatures range from 25 to 30°C. Rainfall is heavy, totalling around 572mm across the season with a monthly average of 191mm. Winds are moderate at around 17km/h. Light, breathable clothing is ideal — perfect conditions for outdoor activities.
Autumn
Temperatures range from 25 to 30°C. Rainfall is heavy, totalling around 1087mm across the season with a monthly average of 362mm. Winds are generally light, averaging 14km/h. A waterproof jacket and sturdy footwear are recommended as rain becomes more frequent.
Winter
Temperatures range from 25 to 31°C. Precipitation is moderate at around 207mm for the season, averaging 69mm per month. Winds are moderate at around 16km/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 São Luís 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.
