2 µg/m³ Low
Bratislava air quality now
Slovakia · The summary is refreshed every 15 minutes.
Bratislava, October 21, 2026: daily mean PM2.5 8 µg/m³ (9 sensors), level “Low” — as in the Atmy Data Hub. Now (20:00 local time): 2.2 µg/m³. Open methodology and data in JSON: Methodology and data sources · JSON
Right now in Bratislava, PM2.5 averages 2.2 µg/m³ — “good” on the US EPA scale (approximate, from hourly readings). Mean of 9 sensors on the Atmy network, readings from 19:54–19:56 local time (17:54–17:56 UTC), summary prepared at 20:00 local time. Median: 1.9 µg/m³; range across sensors: 0.9–5.0 µg/m³.
Bratislava: air quality for the completed day
8 µg/m³ Low
Daily mean PM2.5 on October 21, 2026 (00:00–24:00 UTC): 8 µg/m³ from 9 sensors that passed the quality check — the same value as in the Atmy Data Hub.
LowModerateElevatedHighVery highExtremely high
Air Quality in Slovakia for the Completed Day
Bratislava: PM2.5 by month
Mean
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
This month
7
4
11
15
19
12
9
5
3
3
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.
Where in Bratislava is the air worse?
See all sensors
Highest current reading: 5.0 µg/m³ (SC #84733). Lowest: 0.9 µg/m³ (SC #50737). 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 — 9 sensors.
Atmy shows the networks’ readings after the Data Hub’s quality check: test devices and sensors that fail it are left out.
Slovakia: sensors in total
38
BratislavaSlovakia
9Banská BystricaSlovakia
6ŽilinaSlovakia
6
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: Bratislava
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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Questions
What was the air quality in Bratislava over the last completed day?
Daily mean PM2.5 on October 21, 2026 (00:00–24:00 UTC): 8 µg/m³ from 9 sensors that passed the quality check — the same value as in the Atmy Data Hub. No. 2 of 4 cities in Slovakia and No. 173 of 297 worldwide, from the most polluted.
What is the air quality in Bratislava right now?
Right now in Bratislava, PM2.5 averages 2.2 µg/m³ — “good” on the US EPA scale (approximate, from hourly readings). Mean of 9 sensors on the Atmy network, readings from 19:54–19:56 local time (17:54–17:56 UTC), summary prepared at 20:00 local time. Median: 1.9 µg/m³; range across sensors: 0.9–5.0 µg/m³.
Is it safe to be outdoors in Bratislava 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 Bratislava is the air worse?
Highest current reading: 5.0 µg/m³ (SC #84733). Lowest: 0.9 µg/m³ (SC #50737). 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 Bratislava polluted?
Over the last 365 days with data, the mean daily PM2.5 in Bratislava was 7.2 µg/m³ — 1.4 times the WHO annual guideline (5 µg/m³). Over the last 30 days: 4.4 µg/m³. From Atmy's archive of daily city means.
When is the air in Bratislava cleanest?
In Atmy's daily archive, the cleanest month of the last year was September 2026: 2.3 µg/m³ on average.
When is the air in Bratislava most polluted?
The most polluted month of the last year was January 2026: 17.4 µg/m³ on average.
Is the air in Bratislava worse in the heating season?
From November to March the mean daily PM2.5 was 12.7 µg/m³, from June to August 3.1 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