Modeled air-quality planning
Air quality in São Luís, Maranhão, Brazil: forecast and best time outside
Use this page to check the modeled air-quality outlook for São Luís, Maranhão, Brazil and compare practical periods before making an outdoor plan. The live card uses the same teaser-to-email flow as the main AirAgora tool; the factual context below comes from the licensed GeoNames city record.
- Population rank in directory
- #%!d(float64=616) of 2,500
- Population in source record
- 917,237
Current modeled outlook
Current modeled outlook for São Luís
AirAgora requests the current OpenWeather 1–5 category and source timestamp through the official API. The anonymous card stays concise, while the complete 24-hour comparison remains email-gated.
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GeoNames · CC BY 4.0
GeoNames facts for São Luís
These fields describe the GeoNames populated-place record associated with this page. They do not describe local pollution causes or typical conditions.
- Population in source record
- 917,237
- Population rank in directory
- #%!d(float64=616) of 2,500
- Population rank among included cities in this country
- #%!d(float64=16) of %!d(float64=136) included cities in Brazil
- GeoNames administrative-area label
- Maranhão
- IANA timezone
- America/Fortaleza · UTC-03:00
- Elevation / terrain model
- %!s(float64=29) m (DEM field)
- GeoNames coordinates
- -2.5297°, -44.3028°
- GeoNames record modified
- April 13, 2026
What the place facts mean for this page
São Luís is number %!d(float64=616) in AirAgora's population-ordered city directory. The GeoNames record reports 917,237 residents, within the 500,000–1 million source range.
São Luís is the %!d(float64=16)-ranked included city for Brazil; the corpus contains %!d(float64=136) qualifying cities from that country. São Luís belongs to the South America region and lies in the Southern hemisphere.
The GeoNames DEM field reports %!s(float64=29) m (DEM field), which falls in the broad low-elevation range used in this directory. AirAgora does not infer pollution, climate, or personal exposure from elevation.
Local date, timezone, and clock behavior
Planning windows for São Luís use the IANA timezone America/Fortaleza. On this page's publication date, the local date is Sunday, July 19, 2026 and the UTC offset is UTC-03:00.
The January and July reference offsets are both UTC-03:00. No seasonal offset change appears in the 2026 reference check, although timezone rules can still change in future database releases.
Which provider air-quality scale is shown for São Luís?
AirAgora displays OpenWeather’s official air-pollution scale from 1 to 5. It is not labeled European AQI, U.S. AQI, or a local regulatory index.
The provider category is preserved for display. AirAgora derives continuous internal severity from documented pollutant concentration bands for ranking; that internal value is not a synthetic AQI or a promise of safety.
Modeled forecast and local limits
São Luís uses the OpenWeather modeled air-pollution forecast. The selected coordinate represents provider forecast data, not a street-level monitor, indoor measurement, or personal exposure estimate.
OpenWeather 1–5
The official provider category stays visible and is not relabeled as a regulatory AQI.
Pollutant severity
Internal scoring comes from documented concentration bands and is never presented as a synthetic AQI.
How to use the São Luís planner
Start with the live current-category teaser, choose the activity, then use the email reveal for a complete hourly comparison. AirAgora evaluates complete two-hour windows starting between 06:00 and 22:00 local time. It gives 70% of the score to mean severity and 30% to the worst hour, keeps an earlier window when scores are materially tied, and avoids naming a winner when the difference is too small.%!(EXTRA string=São Luís)
If every practical period remains in a poor category, the result is described as the least polluted available window rather than as good or safe. Missing hours, provider errors, and stale data remain visible instead of being filled with invented values.
Open the best-time-outside toolNearby cities in the validated corpus
Distances below are great-circle approximations between GeoNames city coordinates. They help navigate AirAgora's 2,500-city directory; they are not route distances and do not imply similar air conditions.
Questions about air quality in São Luís
Which air-quality scale does AirAgora show for São Luís, Maranhão, Brazil?
For São Luís, Maranhão, Brazil, AirAgora displays OpenWeather’s official air-pollution scale from 1 to 5. It is not labeled as European, U.S., or local regulatory AQI.
What timezone does the São Luís, Maranhão, Brazil forecast use?
The city record uses America/Fortaleza. Forecast timestamps and candidate windows are converted into that IANA timezone; the 2026 reference offset is UTC-03:00.
Is the São Luís, Maranhão, Brazil result a street-level measurement?
No. It is a modeled OpenWeather air-pollution forecast for the selected coordinate, not a street-level monitor. A nearby station, route, indoor space, or local event can differ.%!(EXTRA string=São Luís, Maranhão, Brazil)
Where does the population figure for São Luís, Maranhão, Brazil come from?
The page reports the GeoNames value of São Luís, Maranhão, Brazil and population rank %!d(string=917,237) in AirAgora's 2,500-city directory. It is source metadata, not a live population estimate.%!(EXTRA float64=616)
Which supported city pages are nearest to São Luís, Maranhão, Brazil?
The nearest city-directory pages are São Luís, Maranhão, Brazil. Distances use city coordinates and are approximate great-circle values, not driving routes.%!(EXTRA string=São José de Ribamar (Brazil), Teresina (Brazil), Ananindeua (Brazil), Belém (Brazil))
What does “best time” mean for São Luís, Maranhão, Brazil?
It means the lowest deterministic score among complete practical two-hour windows returned for São Luís, Maranhão, Brazil. It does not mean risk-free, and when conditions are similarly poor AirAgora says so.%!(EXTRA string=São Luís, Maranhão, Brazil)
When was the São Luís, Maranhão, Brazil place record updated?
The GeoNames record carries the modification date São Luís, Maranhão, Brazil. Live air data has a separate provider update timestamp shown in the result card.%!(EXTRA string=April 13, 2026)
Sources, modification, and limits
Place name, administrative area, coordinates, timezone, population, elevation/DEM, feature code, and modification date come from GeoNames under CC BY 4.0. The GeoNames record used here was last modified on April 13, 2026. Live modeled air-pollution fields come from OpenWeather with visible attribution. AirAgora preserves the provider 1–5 category and separately derives, caches, and scores component severity.
