What changed & when
Onset through peak
Baseline 2026-09-24 · onset 2026-10-08 · peak 2026-10-08 · latest 2026-10-08. Thermal heatwave anomaly (+54% above 30d baseline).

In plain English: São Paulo is 54% above its 30-day Temperature baseline (29.1 vs 18.9). Unusual does not automatically mean unsafe; this is a statistical departure from recent local weather, not an emergency siren.
Gemini may only interpret numbers already on this page. Chart annotations below are computed from the dated series (onset, peak, duration, latest vs baseline). Hypotheses are labeled and are not verified causes.
WHO 24h guideline: 15 µg/m³. EPA band: Moderate. 30-day baseline 18 µg/m³. Statistical anomaly: no. CAMS ozone on this page is 229 µg/m³ CAMS O₃ (mass concentration, not station AQI). · Click for dated trend
30-day baseline 18.9°C · q=0.0333 · Click for dated trend
High today: 29.1°C. 30-day baseline 18.9°C. · Click for dated trend
Dry spell does not automatically mean drought. Baseline 8.2 mm. · Click for dated trend
Wind helps disperse ground-level pollutants. Click for the humidity trend versus other atmospheric measurements. · Click for dated trend
Sun protection recommended during midday hours.
Standard clear atmospheric line of sight.
Optimal range for local urban vegetation.
Travel through satellite observations to discover how this area has changed.
2026-10-08
Temperature 29.1 °C · MODIS land surface temperature (day)
Current · T−1 · T−7 · T−14 · T−30 · NASA GIBS · five snapshots, not a 90-day scrub
What changed & when
Baseline 2026-09-24 · onset 2026-10-08 · peak 2026-10-08 · latest 2026-10-08. Thermal heatwave anomaly (+54% above 30d baseline).
Magnitude & spatial extent
Open the What changed tab to compare baseline and peak pixels. This is a visual aid, not a land-cover map.
Scientific uncertainty
NASA GIBS true-color is typically about one UTC day behind. Clouds, smoke, and missing tiles can hide the surface; they are not evidence that conditions are typical or safe. Pixel differencing is an unvalidated visual comparison (fixed 15% RGB delta and a brightness cloud heuristic). It is not environmental detection. Onset and peak dates come from the city's modeled Open-Meteo / CAMS series, not from the satellite pixels.
Observed: São Paulo has an active heat statistical flag (Thermal heatwave anomaly (+54% above 30d baseline)). Satellite lookback compares a pre-onset baseline on 2026-09-24 with peak 2026-10-08 and latest 2026-10-08. NASA GIBS layer: MODIS_Terra_Land_Surface_Temp_Day. Unusual ≠ unsafe — a radar flag is not a health classification, and a visual delta is not a verified land-cover change product.
Sao Bernardo do Campo Air Quality Index (AQI) and Brazil Air Pollution
Sao Jose do Rio Preto Air Quality Index (AQI) and Brazil Air Pollution
Modifying effects of PM2.5 and O3 on heat-related cardiorespiratory hospitalizations in Brazil | Scientific Reports
Modeled weather: Open-Meteo (ECMWF IFS / GFS blend). Modeled air: Open-Meteo Air Quality (Copernicus CAMS). Observed fire: NASA FIRMS VIIRS 375 m. Observation 2026-10-08T00:00:00Z. Pillar Thermal Heatwave.