Climate Overview
The climate in São Luís is cold. The average annual temperature is -26°C and approximately 188mm of precipitation falls per year. May is the wettest month, receiving around 33mm of rainfall. São Luís sits near the equator, so seasonal temperature differences are minimal throughout the year. Snowfall occurs from January to December, with around 187cm accumulating over the season.
Temperature
Temperatures in São Luís vary considerably across the year, with a 29°C difference between the coldest and warmest months. October is the warmest month, though highs remain moderate at -14°C with a mean of -17°C. July brings the harshest conditions, with lows dropping to -43°C and an average temperature of -42°C. Daily temperature variation is modest, with an average difference of 4°C between highs and lows. The sharpest temperature change occurs between May and June, with a 15°C shift in average temperatures.
Precipitation
São Luís is a quite dry location, receiving approximately 188mm of precipitation annually, which averages out to around 16mm per month. The wettest month is April, averaging 33mm of rainfall. May and October also tend to see above-average precipitation. The driest month is July, with just 2mm. That's 31mm less than April, 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. Snowfall is a regular feature from January to December, with around 187cm accumulating over the season. April typically sees the most snow at around 33cm.
Wind
São Luís is relatively calm, with an average annual wind speed of 8km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is September, averaging 11km/h, though still comfortable for most outdoor activities. The calmest conditions occur in January, with average winds dropping to 5km/h, making it an ideal period for wind-sensitive activities. Wind speeds vary significantly across the year, with a 6km/h difference between the calmest and windiest months. This level of variation is worth factoring into travel plans.
Seasons
16 days until Spring
It is currently winter in São Luís, which began on June 21, 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 -14°C, while the coldest stretch bottoms out in July near -43°C. Spring is next, beginning on September 23, 2026 — 16 days from now.
Spring
Temperatures range from -32 to -14°C. Rainfall is relatively light, with around 66mm over the season and a monthly average of 22mm. Winds are generally light, averaging 10km/h. Light layers work well as temperatures warm through the season — a great time to be outdoors.
Summer
Temperatures range from -39 to -20°C. Precipitation is minimal, with only around 16mm for the entire season. Winds are generally light, averaging 7km/h. Comfortable clothing with a light layer for cooler evenings is all you need.
Autumn
Temperatures range from -20 to -16°C. Rainfall is relatively light, with around 88mm over the season and a monthly average of 29mm. Expect around 88cm of snow accumulation during this period. Winds are generally light, averaging 9km/h. Layered clothing works best as temperatures gradually cool — enjoy the crisp air and changing scenery.
Winter
Temperatures range from -43 to -31°C. Precipitation is minimal, with only around 18mm for the entire season. Expect around 18cm of snow accumulation during this period. Winds are generally light, averaging 8km/h. Heavy layering and insulated outerwear are essential — exposed skin should be minimised outdoors.
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. Snow is measured in centimetres (cm) and reflects average monthly snowfall accumulation. 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.
