A practical guide to AQI, pollutants and hotspots so you can actually
understand what Диши.мк (and other maps) are showing — and what it means
for everyday life in Skopje.
Focus: PM₂.₅, PM₁₀, NO₂Context: Skopje valley & winter heating
1. AQI vs µg/m³ — what are we actually looking at?
Dashboards usually show an Air Quality Index (AQI) and/or raw
concentrations in micrograms per cubic metre (µg/m³). They describe the
same situation, just in different formats.
Air Quality Index (AQI)
AQI is a scaled number (often 0–500) constructed from pollutant
concentrations. It translates “hard chemistry” into “how risky is this
for health right now?”. Values around 0–50 are usually classified as
“Good”, 51–100 as “Moderate”, and higher bands step into levels where
sensitive groups and then the general population are affected.
On Диши.мк, AQI gives you a quick health-oriented view — not just
whether a legal limit is passed, but if the air is clean enough for
normal outdoor activity.
µg/m³ — the raw concentration
Concentration is the physical amount of pollutant in the air:
micrograms of a pollutant per cubic metre of air. For example, PM₂.₅ =
35 µg/m³ means every cubic metre contains 35 micrograms of fine
particles ≤ 2.5 µm in diameter.
WHO guidelines, EU directives and health studies mostly use µg/m³.
AQI is a “compressed” version that helps you interpret those values
quickly without needing to remember every limit value.
2. The key pollutants in Skopje
Skopje’s air is dominated by particles (PM₂.₅, PM₁₀) and nitrogen dioxide (NO₂).
Ozone (O₃) and sulphur dioxide (SO₂) appear more in specific seasons or local
conditions.
PM₂.₅
Fine particles ≤ 2.5 µm
Very small particles that can reach deep into the lungs and enter the
bloodstream. Long-term exposure is strongly linked to cardiovascular
disease, stroke, lung cancer and worsening asthma.
In Skopje, PM₂.₅ peaks in winter, when solid-fuel heating, traffic and
stagnant air all stack on top of each other.
PM₁₀
Coarse particles ≤ 10 µm
Larger particles that mainly irritate the upper airways, eyes and
throat. Typical sources: road dust, construction, traffic and burning
fuels.
In Skopje, PM₁₀ often spikes on dry, windy days with a lot of traffic
and construction, and during winter episodes with heavy heating.
NO₂
Nitrogen dioxide
A gas mostly from vehicle exhaust and combustion processes. Short-term
peaks can trigger asthma attacks and airway irritation; long-term
exposure is linked to reduced lung function and more respiratory
disease.
In Skopje, NO₂ is usually highest along busy roads and intersections
with slow-moving traffic.
O₃
Ozone
A secondary pollutant that forms from reactions between NOₓ and
volatile organic compounds under sunlight. It irritates lungs and can
reduce performance even in healthy people.
Ozone is more of a summer and early-autumn issue in Skopje; winter
days are dominated by particles and NO₂.
3. Why Skopje’s pollution episodes are so intense
Skopje’s geography and energy use patterns create very strong winter
episodes. It’s not just “bad air” — it’s a specific physical setup.
1) Valley + temperature inversion
Skopje lies in a basin. In cold, calm conditions a temperature
inversion forms: a layer of warmer air above colder air near the
ground. That “lid” prevents mixing, so emissions from chimneys and
traffic stay trapped close to where people are.
On a map, this looks like several stations in different
neighbourhoods rising together — not just one isolated hotspot.
2) Solid-fuel heating + traffic
Winter studies for Skopje show that residential heating with wood and
coal stoves and older boilers is a major source of PM₂.₅ and PM₁₀.
Traffic, especially older diesel vehicles and congestion, adds NO₂ and
more particles along main corridors.
Evening and early-morning peaks match when stoves are running, people
travel, and the valley is still “closed”.
4. How to use the Диши.мк data views together
The point is not to stare at a single AQI number, but to build a quick,
structured picture: where it’s bad, for how long, and compared to what.
Step 1
Hotspots: where is it worst?
Start with the Hotspots page. If multiple stations across the city are
in the same high category, you’re dealing with a city-wide episode. If
only one station is high, it might be a more local issue or a
micro-environment (e.g. very close to a busy road).
Step 2
Hourly line: is it getting better or worse?
Hourly trends tell you the “direction of travel”. Falling values with
more wind usually mean improvement. Rapid evening rises with low wind
suggest a strong night-time episode, especially in winter.
Step 3
Episodes & trends: is this “normal”?
Episodes and Trends (once live) show how current conditions compare to
past winters and past years. That context is important for media,
schools and citizens arguing for structural changes, not just reacting
to today’s spike.
5. Everyday decisions this data can actually support
Диши.мк is not a medical service, but it can help with basic exposure
choices for yourself, your family and your community.
Ventilation & outdoor time
Good / Moderate AQI: normal airing of homes, outdoor
walks and exercise away from heavy traffic are usually fine for most
people.
Unhealthy for sensitive groups: children, older
adults and people with asthma or heart disease should reduce longer
outdoor exposure near roads and consider ventilating when values dip.
Unhealthy or worse: shorten time spent near busy
streets, shift intense activity indoors where air is cleaner, and
use short, targeted ventilation moments.
Community & policy use
Use repeated winter peaks in specific neighbourhoods as evidence for
targeted clean-heating programmes and insulation upgrades.
Combine station data with traffic patterns to argue for low-emission
zones, better public transport and safer walking / cycling routes.
Track whether strong measures (fuel bans, boiler replacement,
building retrofits) actually change the frequency and intensity of
episodes over several winters.