Brno: air quality for the completed day
6 µg/m³ Low
Daily mean PM2.5 on October 21, 2026 (00:00–24:00 UTC): 6 µg/m³ from 4 sensors that passed the quality check — the same value as in the Atmy Data Hub.
LowModerateElevatedHighVery highExtremely high
Brno air quality now
Czechia · The summary is refreshed every 15 minutes.
October 22
The air is clean now
Brno
12°C
Clear
13AQI
1020hPa
Atmospheric
pressure
52%
Humidity
Brno, October 21, 2026: daily mean PM2.5 6 µg/m³ (4 sensors), level “Low” — as in the Atmy Data Hub. Now (20:00 local time): 2.3 µg/m³. Open methodology and data in JSON: Methodology and data sources · JSON
Right now in Brno, PM2.5 averages 2.3 µg/m³ — “good” on the US EPA scale (approximate, from hourly readings). Mean of 4 sensors on the Atmy network, readings from 19:55–19:56 local time (17:55–17:56 UTC), summary prepared at 20:00 local time. Median: 2.5 µg/m³; range across sensors: 0.8–3.6 µg/m³.
In Brno the air is good right now (approximate, US EPA scale). From 07:00 to 20:00 local time the city mean PM2.5 stayed roughly level: from 1.3 to 2.3 µg/m³.
The weather data do not point to a clear reason for this level.
Weather now: clear, 12°C, wind 2 m/s, humidity 52%. No major change in the wind is expected in the coming hours. By 07:00 the temperature will be about 3°C.
Written automatically at 20:00 local time (18:00 UTC) from sensor measurements and the weather forecast. Values are approximate; hypotheses are marked.
7 km/h
Wind, WNW
3.5 mm
Precipitation today
Air Quality in Czechia for the Completed Day
Brno: PM2.5 by month
Mean
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
This month
5
3
7
7
8
7
7
4
2
2
3
3
2
5
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
25%An estimate of weather conditions · not a PM2.5 forecast
Now2515
20.0004.0011.0019.00
Pollution accumulation forecast
Today — October 22
14°/6°
Index by time of day
30/100Low
- 29/100
Night - 26/100
Morning - 7/100
Day - 30/100
Evening
Friday — October 23
14°/3°
Index by time of day
62/100Moderate
- 62/100Night
- 43/100Morning
- 7/100Day
- 22/100Evening
Saturday — October 24
13°/5°
Index by time of day
48/100Moderate
- 48/100Night
- 43/100Morning
- 6/100Day
- 29/100Evening
Sunday — October 25
9°/4°
Index by time of day
60/100Moderate
- 60/100Night
- 39/100Morning
- 6/100Day
- 24/100Evening
Monday — October 26
14°/4°
Index by time of day
58/100Moderate
- 58/100Night
- 45/100Morning
- 8/100Day
- 26/100Evening
Tuesday — October 27
12°/5°
Index by time of day
56/100Moderate
- 56/100Night
- 41/100Morning
- 8/100Day
- 24/100Evening
Forecast of conditions that trap pollution near the surface
Weather
12°
Clear. Feels like 9°C
- Morning
11°C74% - Day
12°C55% - Evening7°C85%
Wind
7km/hWind from the WNW
22km/hWind gusts
Wind force: 2
Gusts up to 22 km/h are expected.
10-day weather forecast for Brno
Czechia
- TodayOct 2214°C6°C
- FriOct 23
14°C3°C - SatOct 2413°C5°C
- SunOct 259°C4°C
- MonOct 26
14°C4°C - TueOct 2712°C5°C
- WedOct 2811°C6°C
- ThuOct 2913°C7°C
- FriOct 3014°C5°C
- SatOct 3111°C6°C
Where in Brno is the air worse?
See all sensors
Highest current reading: 3.6 µg/m³ (SC #98388). Lowest: 0.8 µg/m³ (SC #2632). The list shows every sensor, highest first.
- Good
- Moderate
- Unhealthy for sensitive groups
- Unhealthy
- Very unhealthy
- Hazardous
Source: atmy.ai monitoring network
Who provides the data
Sensors in the summary by network: Sensor.Community — 4 sensors.
Atmy shows the networks’ readings after the Data Hub’s quality check: test devices and sensors that fail it are left out.
Czechia: sensors in total
110
PragueCzechia
37LiberecCzechia
14Karlovy VaryCzechia
10
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: Brno
Daily mean PM2.5 of the city sensors, µg/m³
Click a day to see its date and value.
LowModerateElevatedHighVery highExtremely high
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A card with the current PM2.5 in Brno: it is refreshed every 15 minutes and links to this page. Paste the code into your site.
Czechia · City ranking · All pilot cities
Questions
What was the air quality in Brno over the last completed day?
Daily mean PM2.5 on October 21, 2026 (00:00–24:00 UTC): 6 µg/m³ from 4 sensors that passed the quality check — the same value as in the Atmy Data Hub. No. 9 of 9 cities in Czechia and No. 213 of 297 worldwide, from the most polluted.
What is the air quality in Brno right now?
Right now in Brno, PM2.5 averages 2.3 µg/m³ — “good” on the US EPA scale (approximate, from hourly readings). Mean of 4 sensors on the Atmy network, readings from 19:55–19:56 local time (17:55–17:56 UTC), summary prepared at 20:00 local time. Median: 2.5 µg/m³; range across sensors: 0.8–3.6 µg/m³.
Is it safe to be outdoors in Brno 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 Brno is the air worse?
Highest current reading: 3.6 µg/m³ (SC #98388). Lowest: 0.8 µg/m³ (SC #2632). 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 Brno polluted?
Over the last 349 days with data, the mean daily PM2.5 in Brno was 4.8 µg/m³ — within the WHO annual guideline (5 µg/m³). Over the last 30 days: 3.9 µg/m³. From Atmy's archive of daily city means.
When is the air in Brno cleanest?
In Atmy's daily archive, the cleanest month of the last year was May 2026: 2.1 µg/m³ on average.
When is the air in Brno most polluted?
The most polluted month of the last year was January 2026: 9.4 µg/m³ on average.
Is the air in Brno worse in the heating season?
From November to March the mean daily PM2.5 was 7.7 µg/m³, from June to August 2.8 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