France · The summary is refreshed every 15 minutes.
No current value: fewer than four sensors at different places are reporting now.
Saint-Étienne, November 10, 2026: daily mean PM2.5 6 µg/m³ (4 sensors), level “Low” — as in the Atmy Data Hub. Open methodology and data in JSON: Methodology and data sources · JSON
There are not enough fresh measurements for Saint-Étienne right now. From 10:00 to 18:00 local time the city mean PM2.5 rose from 8.8 to 14.0 µg/m³.
Light wind (1 m/s) in the evening or at night, as the air cools, possibly traps particles near the ground (a temperature inversion). High humidity (87%) possibly makes optical sensors read somewhat higher.
Weather now: cloudy, 12°C, wind 1 m/s, humidity 87%. Precipitation is expected around 05:00; it may wash particles out.
Written automatically at 22:10 local time (21:10 UTC) from sensor measurements and the weather forecast. Values are approximate; hypotheses are marked.
1 m/s
Wind, WNW
0.4 mm
Precipitation today
6 µg/m³ Low
Daily mean PM2.5 on November 10, 2026 (00:00–24:00 UTC = 01:00–01:00 UTC+1): 6 µg/m³ from 4 sensors that passed the quality check — the same value as in the Atmy Data Hub.
26/100Low · An estimate of weather conditions · not a PM2.5 forecast
19°/12°
Index by time of day
51/100Moderate
Night
Morning
Day
Evening13°/10°
Index by time of day
41/100Moderate
NightMorningDayEvening10°/2°
Index by time of day
32/100Low
NightMorningDayEvening14°/-1°
Index by time of day
61/100Moderate
NightMorningDayEvening14°/9°
Index by time of day
51/100Moderate
NightMorningDayEvening13°/6°
Index by time of day
40/100Moderate
NightMorningDayEveningForecast of conditions that trap pollution near the surface
12°
Cloudy. Feels like 11°C
13°C93%19°C60%12°C88%1m/sWind from the WNW
1m/sWind gusts
Wind force: 1
Light wind is expected over the next few hours.
France
19°C12°C13°C10°C10°C2°C14°C-1°C14°C9°C13°C6°C16°C7°C14°C10°C
13°C8°C11°C7°C207
RennesFrance
20ToulouseFrance
18VilleurbanneFrance
16Cities 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.
France · City ranking · All pilot cities
Daily mean PM2.5 on November 10, 2026 (00:00–24:00 UTC = 01:00–01:00 UTC+1): 6 µg/m³ from 4 sensors that passed the quality check — the same value as in the Atmy Data Hub. No. 29 of 32 cities in France and No. 598 of 676 worldwide, from the most polluted.
Fresh data for Saint-Étienne are insufficient (last update: 11:30 local time, 10:30 UTC). Open the map for the latest readings of individual sensors.
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.
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
