Germany · The summary is refreshed every 15 minutes.
October 22
The air is moderate now
Bielefeld
12°C
Partly cloudy
51AQI
1013hPa
Atmospheric
pressure
73%
Humidity
Bielefeld, October 21, 2026: daily mean PM2.5 20 µg/m³ (40 sensors), level “Moderate” — as in the Atmy Data Hub. Now (20:00 local time): 9.2 µg/m³. Open methodology and data in JSON: Methodology and data sources · JSON
Right now in Bielefeld, PM2.5 averages 9.2 µg/m³ — “moderate” on the US EPA scale (approximate, from hourly readings). Mean of 39 sensors on the Atmy network, readings from 19:52–19:57 local time (17:52–17:57 UTC), summary prepared at 20:00 local time. Median: 1.4 µg/m³; range across sensors: 0.4–271.9 µg/m³.
In Bielefeld the air is moderate right now (approximate, US EPA scale). From 07:00 to 20:00 local time the city mean PM2.5 rose from 6.6 to 9.2 µg/m³. The highest hour was 16:00 with 11.1 µg/m³.
The weather data do not point to a clear reason for this level.
Weather now: partly cloudy, 12°C, wind 5 m/s, humidity 73%. Precipitation is expected around 04:00; it may wash particles out.
Written automatically at 20:00 local time (18:00 UTC) from sensor measurements and the weather forecast. Values are approximate; hypotheses are marked.
18 km/h
Wind, SSW
0 mm
Precipitation today
20 µg/m³ Moderate
Daily mean PM2.5 on October 21, 2026 (00:00–24:00 UTC): 20 µg/m³ from 40 sensors that passed the quality check — the same value as in the Atmy Data Hub.
Monthly means of quality-checked sensors, as in the Data Hub trend; the current month is still incomplete, “-” means no data.
17%An estimate of weather conditions · not a PM2.5 forecast
12°/7°
Index by time of day
37/100Moderate
Night
Morning
Day
Evening13°/9°
Index by time of day
46/100Moderate
NightMorningDayEvening11°/8°
Index by time of day
36/100Moderate
NightMorningDayEvening12°/9°
Index by time of day
27/100Low
NightMorningDayEvening12°/8°
Index by time of day
36/100Moderate
NightMorningDayEvening17°/11°
Index by time of day
38/100Moderate
NightMorningDayEveningForecast of conditions that trap pollution near the surface
12°
Partly cloudy. Feels like 8°C
7°C82%
12°C67%10°C82%18km/hWind from the SSW
40km/hWind gusts
Wind force: 3
Gusts up to 40 km/h are expected.
Germany
12°C7°C
13°C9°C11°C8°C12°C9°C12°C8°C17°C11°C
15°C8°C14°C6°C13°C6°C13°C6°C
Highest current reading: 271.9 µg/m³ (SC #2019). Lowest: 0.4 µg/m³ (SC #31262). The list shows every sensor, highest first.
Source: atmy.ai monitoring network
Sensors in the summary by network: Sensor.Community — 39 sensors.
Atmy shows the networks’ readings after the Data Hub’s quality check: test devices and sensors that fail it are left out.
2,617
StuttgartGermany
195BerlinGermany
195HamburgGermany
168Cities 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.
Daily mean PM2.5 of the city sensors, µg/m³
Click a day to see its date and value.
A card with the current PM2.5 in Bielefeld: it is refreshed every 15 minutes and links to this page. Paste the code into your site.
Germany · City ranking · All pilot cities
Daily mean PM2.5 on October 21, 2026 (00:00–24:00 UTC): 20 µg/m³ from 40 sensors that passed the quality check — the same value as in the Atmy Data Hub. No. 7 of 77 cities in Germany and No. 25 of 297 worldwide, from the most polluted.
Right now in Bielefeld, PM2.5 averages 9.2 µg/m³ — “moderate” on the US EPA scale (approximate, from hourly readings). Mean of 39 sensors on the Atmy network, readings from 19:52–19:57 local time (17:52–17:57 UTC), summary prepared at 20:00 local time. Median: 1.4 µg/m³; range across sensors: 0.4–271.9 µg/m³.
The current level is “moderate” (US EPA scale, approximate). Unusually sensitive people should consider reducing prolonged or heavy exertion outdoors. This is the standard guidance of the scale, not medical advice.
Highest current reading: 271.9 µg/m³ (SC #2019). Lowest: 0.4 µg/m³ (SC #31262). The list shows every sensor, highest first.
From Atmy sensors and connected public networks (citizen, experimental and government monitors), aggregated by Atmy. Values are approximate; see the methodology.
The summary is rebuilt every 15 minutes from the latest reading of each sensor, each no older than one hour.
Over the last 365 days with data, the mean daily PM2.5 in Bielefeld was 10.2 µg/m³ — 2.0 times the WHO annual guideline (5 µg/m³). Over the last 30 days: 9.2 µg/m³. From Atmy's archive of daily city means.
In Atmy's daily archive, the cleanest month of the last year was June 2026: 4.8 µg/m³ on average.
The most polluted month of the last year was February 2026: 14.8 µg/m³ on average.
From November to March the mean daily PM2.5 was 13.7 µg/m³, from June to August 7.6 µg/m³ (last 365 days).
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
