Bulgaria · The summary is refreshed every 15 minutes.
No current value: fewer than four sensors at different places are reporting now.
Open methodology and data in JSON: Methodology and data sources · JSON
In Smolyan the air is moderate right now (approximate, US EPA scale). From 11:00 to 22:00 local time the city mean PM2.5 rose from 3.3 to 25.0 µg/m³. The highest hour was 18:00 with 40.0 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 (89%) possibly makes optical sensors read somewhat higher.
Weather now: partly cloudy, 9°C, wind 1 m/s, humidity 89%. By 11:00 the wind is expected to pick up to 4 m/s, which may clear the air. By 11:00 the temperature will be about 16°C.
Written automatically at 23:13 local time (21:13 UTC) from sensor measurements and the weather forecast. Values are approximate; hypotheses are marked.
1 m/s
Wind, WNW
0 mm
Precipitation today
Monthly means of quality-checked sensors, as in the Data Hub trend; the current month is still incomplete, “-” means no data.
44/100Moderate · An estimate of weather conditions · not a PM2.5 forecast
16°/9°
Index by time of day
49/100Moderate
Night
Morning
Day
Evening14°/12°
Index by time of day
42/100Moderate
NightMorningDayEvening14°/6°
Index by time of day
37/100Moderate
NightMorningDayEvening6°/0°
Index by time of day
56/100Moderate
NightMorningDayEvening9°/-1°
Index by time of day
53/100Moderate
NightMorningDayEvening12°/3°
Index by time of day
49/100Moderate
NightMorningDayEveningForecast of conditions that trap pollution near the surface
9°
Partly cloudy. Feels like 7°C
13°C76%16°C67%13°C84%1m/sWind from the WNW
3m/sWind gusts
Wind force: 1
Light wind is expected over the next few hours.
Bulgaria
16°C9°C14°C12°C
14°C6°C6°C0°C9°C-1°C
12°C3°C14°C2°C15°C9°C17°C5°C488
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30Cities 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.
Bulgaria · City ranking · All pilot cities
Fresh data for Smolyan are insufficient (last update: 01:45 local time, 23:45 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.
Over the last 267 days with data, the mean daily PM2.5 in Smolyan was 20.6 µg/m³ — 4.1 times the WHO annual guideline (5 µg/m³). Over the last 30 days: — µg/m³. From Atmy's archive of daily city means.
In Atmy's daily archive, the cleanest month of the last year was May 2026: 4.8 µg/m³ on average.
The most polluted month of the last year was September 2026: 46.8 µg/m³ on average.
From November to March the mean daily PM2.5 was 17.4 µg/m³, from June to August 16.1 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
