São Leopoldo air quality now

Brazil · The summary is refreshed every 15 minutes.

October 22

The air is clean now

São Leopoldo

28°C

Partly cloudy

27AQI

1015hPa

Atmospheric
pressure

55%

Humidity

São Leopoldo, October 21, 2026: daily mean PM2.5 5 µg/m³ (5 sensors), level “Low” — as in the Atmy Data Hub. Now (15:00 local time): 4.9 µg/m³. Open methodology and data in JSON: Methodology and data sources · JSON

Right now in São Leopoldo, PM2.5 averages 4.9 µg/m³ — “good” on the US EPA scale (approximate, from hourly readings). Mean of 5 sensors on the Atmy network, readings from 14:54–14:57 local time (17:54–17:57 UTC), summary prepared at 15:00 local time. Median: 4.1 µg/m³; range across sensors: 1.3–9.0 µg/m³.

In São Leopoldo the air is good right now (approximate, US EPA scale). From 02:00 to 15:00 local time the city mean PM2.5 fell from 7.0 to 4.9 µg/m³. The highest hour was 03:00 with 8.4 µg/m³.

The weather data do not point to a clear reason for this level.

Weather now: partly cloudy, 28°C, wind 3 m/s, humidity 55%. Precipitation is expected around 23:00; it may wash particles out. By 02:00 the temperature will be about 18°C.

Written automatically at 15:00 local time (18:00 UTC) from sensor measurements and the weather forecast. Values are approximate; hypotheses are marked.

11 km/h

Wind, ESE

0 mm

Precipitation today

São Leopoldo: air quality for the completed day

Metric: PM2.5, µg/m³ · Color scale: EPA AQI · October 21, 2026 · 00:00–24:00 UTC

5 µg/m³ Low

Daily mean PM2.5 on October 21, 2026 (00:00–24:00 UTC): 5 µg/m³ from 5 sensors that passed the quality check — the same value as in the Atmy Data Hub.

No. 1 of 1 cities in Brazil and No. 233 of 297 worldwide, from the most polluted.

LowModerateElevatedHighVery highExtremely high

São Leopoldo: PM2.5 by month

Metric: PM2.5, µg/m³ · Color scale: EPA AQI

Mean
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
This month
5
2
2
2
3
3
10
10
4
5
4
5
5
4

Monthly means of quality-checked sensors, as in the Data Hub trend; the current month is still incomplete, “-” means no data.

Pollution accumulation index now

4%An estimate of weather conditions · not a PM2.5 forecast

Now45
15.0023.0006.0014.00

Pollution accumulation forecast

Today — October 22

28°/15°

Index by time of day

55/100Moderate

  1. 55/100Night
  2. 43/100Morning
  3. 7/100Day
  4. 20/100Evening

Friday — October 23

28°/18°

Index by time of day

49/100Moderate

  1. 49/100Night
  2. 38/100Morning
  3. 7/100Day
  4. 23/100Evening

Saturday — October 24

26°/18°

Index by time of day

48/100Moderate

  1. 48/100Night
  2. 33/100Morning
  3. 8/100Day
  4. 22/100Evening

Sunday — October 25

20°/15°

Index by time of day

37/100Moderate

  1. 37/100Night
  2. 25/100Morning
  3. 7/100Day
  4. 23/100Evening

Monday — October 26

21°/13°

Index by time of day

59/100Moderate

  1. 59/100Night
  2. 43/100Morning
  3. 6/100Day
  4. 23/100Evening

Tuesday — October 27

24°/11°

Index by time of day

56/100Moderate

  1. 56/100Night
  2. 40/100Morning
  3. 6/100Day
  4. 18/100Evening

Forecast of conditions that trap pollution near the surface

Weather

28°

Partly cloudy. Feels like 31°C

  1. MorningClear22°C70%
  2. DayCloudy26°C60%
  3. EveningCloudy21°C81%

Wind

11km/hWind from the ESE

29km/hWind gusts

Wind force: 2

Gusts up to 36 km/h are expected.

10-day weather forecast for São Leopoldo

Brazil

  1. TodayOct 22Rain28°C15°C
  2. FriOct 23Rain28°C18°C
  3. SatOct 24Rain26°C18°C
  4. SunOct 25Rain20°C15°C
  5. MonOct 26Rain21°C13°C
  6. TueOct 27Cloudy24°C11°C
  7. WedOct 28Rain25°C16°C
  8. ThuOct 29Rain25°C15°C
  9. FriOct 30Rain24°C17°C
  10. SatOct 31Fog25°C15°C

Where in São Leopoldo is the air worse?

See all sensors

Highest current reading: 9.0 µg/m³ (SC #66704). Lowest: 1.3 µg/m³ (SC #61875). The list shows every sensor, highest first.

  1. SC #66704 →9 µg/m³
  2. SC #97224 →6 µg/m³
  3. SC #89041 →4 µg/m³
  4. SC #89460 →4 µg/m³
  5. SC #61875 →1 µg/m³

Source: atmy.ai monitoring network

Who provides the data

Sensors in the summary by network: Sensor.Community — 5 sensors.

Atmy shows the networks’ readings after the Data Hub’s quality check: test devices and sensors that fail it are left out.

Brazil: sensors in total

11

  1. São LeopoldoBrazil

    5

  2. GravataíBrazil

    1

  3. Poços de CaldasBrazil

    1

Cities with the most sensors

All sensors on the map, by city as the map assigns them; the city’s values count only the sensors that pass the Data Hub’s quality check.

Air quality calendar: São Leopoldo

Daily mean PM2.5 of the city sensors, µg/m³

Click a day to see its date and value.

LowModerateElevatedHighVery highExtremely high

Widget for your site

A card with the current PM2.5 in São Leopoldo: it is refreshed every 15 minutes and links to this page. Paste the code into your site.

Air quality in São Leopoldo now — Atmy

Brazil · City ranking · All pilot cities

Questions

What was the air quality in São Leopoldo over the last completed day?

Daily mean PM2.5 on October 21, 2026 (00:00–24:00 UTC): 5 µg/m³ from 5 sensors that passed the quality check — the same value as in the Atmy Data Hub. No. 1 of 1 cities in Brazil and No. 233 of 297 worldwide, from the most polluted.

What is the air quality in São Leopoldo right now?

Right now in São Leopoldo, PM2.5 averages 4.9 µg/m³ — “good” on the US EPA scale (approximate, from hourly readings). Mean of 5 sensors on the Atmy network, readings from 14:54–14:57 local time (17:54–17:57 UTC), summary prepared at 15:00 local time. Median: 4.1 µg/m³; range across sensors: 1.3–9.0 µg/m³.

Is it safe to be outdoors in São Leopoldo now?

The current level is “good” (US EPA scale, approximate). Air quality is satisfactory; no restrictions are recommended. This is the standard guidance of the scale, not medical advice.

Where in São Leopoldo is the air worse?

Highest current reading: 9.0 µg/m³ (SC #66704). Lowest: 1.3 µg/m³ (SC #61875). The list shows every sensor, highest first.

Where do these data come from?

From Atmy sensors and connected public networks (citizen, experimental and government monitors), aggregated by Atmy. Values are approximate; see the methodology.

How often is this page updated?

The summary is rebuilt every 15 minutes from the latest reading of each sensor, each no older than one hour.

Is the air in São Leopoldo polluted?

Over the last 357 days with data, the mean daily PM2.5 in São Leopoldo was 4.7 µg/m³ — within the WHO annual guideline (5 µg/m³). Over the last 30 days: 4.0 µg/m³. From Atmy's archive of daily city means.

When is the air in São Leopoldo cleanest?

In Atmy's daily archive, the cleanest month of the last year was November 2025: 2.2 µg/m³ on average.

When is the air in São Leopoldo most polluted?

The most polluted month of the last year was March 2026: 10.3 µg/m³ on average.

Is the air in São Leopoldo worse in the heating season?

From November to March the mean daily PM2.5 was 4.2 µg/m³, from June to August 4.7 µg/m³ (last 365 days).

Data

Where do these data come from?

The daily value is the Data Hub’s: the mean of the city’s sensors that passed the nightly quality check, each with at least 12 valid hours, and only with sensors at four places 500 m apart; days are UTC.

“Now” uses the same sensors and rule: the mean of their latest readings, each at most 60 minutes old, shown only with sensors at four places 500 m apart reporting.

Source: public Atmy monitoring data. Methodology and data sources · Data terms