Weather in Sao Luis in September 2025
- September is usually the driest month of the year in Sao Luis
Average weather
Average temperature in Sao Luis in September
Going from a maximum of +91°F during the day to a minimum of +77°F during the night, the temperature in September averages around +90°F.
The average maximum temperature goes up 25% by the end of the month, compared with the beginning of the month, from +86°F to +90°F.
Is Sao Luis warm or cold in September?
Sao Luis is typically hot in September.
Maximum temperatures go up compared to the previous month from +88°F to +88°F. The minimum temperature also goes up from +77°F to +79°F.
Make sure that you pack your summer linen and swimming costumes; it’s probably going to be hot.
Take a look at how September is compared to other months in Sao Luis:
Climate in Sao Luis in September
| August | September | October | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +88°F | +88°F | +88°F | ||||
| Min. temperature | ||||||
| +72°F | +73°F | +72°F | ||||
| Max. temperature | ||||||
| +93°F | +93°F | +95°F | ||||
| Rainfall | ||||||
| 29 mm | 13 mm | 13 mm | ||||
| Wind | ||||||
| 3 m/s | 4 m/s | 5 m/s | ||||
| Humidity | ||||||
| 77% | 75% | 75% | ||||
| Air pressure | ||||||
| 1012 HPa | 1011 HPa | 1010 HPa | ||||
| Sunny days | ||||||
| 6 | 9 | 6 | ||||
| Cloudy days | ||||||
| 3 | 7 | 12 | ||||
| Rainy days | ||||||
| 21 | 13 | 12 | ||||
| Snowy days | ||||||
| 0 | 0 | 0 | ||||
September weather is still as good as in August. The temperature levels stay the same in the area of +88°F for average maximum temperature during the day. As September arrives, the amount of rainfall goes down. On average, the rainfall volume decreases from 29 mm to 13 mm. It feels drier, as humidity decreases from 77% to 75%. Winds are stronger in comparison to August, going up from 3 m/s to 4 m/s on average. The good news is there are likely to be more sunny days in September, from 6 to 9.
October brings much the same weather, it remains good.
Wind
The average wind speed is 5 m/s getting up to 6 m/s which is a medium breeze. You can feel it, especially getting out of the water.
The average wind speed in Sao Luis is gradually increasing during September, going from 5 m/s to 5 m/s over the course of the month.
Rain
How was the weather last September in Sao Luis?
Climate Change Over the Years
The climate in Sao Luis in September has not changed that much over the last 43 years.
The average temperature was the lowest in 1985 (+84°F) and the highest in 2017 (+88°F). The driest year was 1983 with only 1125 mm of rainfall, and the wettest year was 1985 with 3380 mm.
FAQ
Is September a good time to visit Sao Luis?
Can you sunbathe in Sao Luis in September?
Is Sao Luis rainy in September?
Is it sunny in Sao Luis in September?
Other cities in Brazil
Monthly weather in Sao Luis
Source of the data
For this page, we’ve looked at the typical weather in Sao Luis, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.
