Air quality in Sweden: where to check and what to do

Short answer. SMHI, the Swedish weather and hydrology institute, publishes an air quality index for monitoring stations around Sweden, based on the last hour's preliminary measurements ¹. It has six levels. From level 4 ("unhealthy"), even healthy people should limit strenuous outdoor activity; at level 6 ("extremely unhealthy"), avoid it and preferably stay indoors more ¹. A fire with toxic smoke can trigger an Important Public Announcement (VMA) ².

Where can I check air quality right now?

SMHI's air quality index shows current conditions at monitoring stations around Sweden, based on preliminary hourly values of common air pollutants ¹. The index was developed by the European Environment Agency and builds on the WHO air quality guidelines ¹.

Read it with care. Values are not yet quality-checked when published, and the index is shown only where pollution is measured continuously and reported in real time ¹. Street stations are placed where people meet the highest concentrations and mostly represent the busiest traffic environments; urban background stations better represent general exposure in a town ¹.

What do the index levels mean?

SMHI's official scale, with its advice ¹:

Risks rise especially when a level lasts more than a few hours ¹. See Air quality index explained and Polluted air and sensitive people.

How polluted is the air on average?

The population-weighted median of Swedish cities shows about 6 µg/m³ of PM2.5 (annual mean 2021-2023) ⁴, just above the WHO guideline of 5 µg/m³ ⁶. Nitrogen dioxide is about 3.9 µg/m³ ⁵, below the WHO guideline of 10 µg/m³ ⁶. That NO2 figure is a regional background over roughly 80 km: a busy street will be higher. These are city medians, not the air in your street.

What should I do on a bad air day, or with smoke or dust?

Follow SMHI's advice for your index level, and go indoors and close windows and doors when the outdoor warning siren sounds ¹³.

• High index level: follow SMHI's advice for your level: watch for symptoms if you have heart or lung disease, cut strenuous outdoor effort, and stay indoors more at levels 5 and 6 ¹. See Pollution episodes and Children and polluted air.
• Important Public Announcement (VMA): a VMA is a general warning for serious incidents of any kind; a fire with toxic smoke is one example ². MCF's instruction when the outdoor warning siren sounds applies to every VMA, not to smoke alone: go indoors, close all windows and doors and, if possible, switch off the ventilation, then listen to Sveriges Radio P4 ³. How warnings reach you is on our Sweden alerts page.
• Wildfire smoke and dust: see Wildfire smoke, A clean-air room at home, Masks for smoke and Dust storms.

A household plan can note who at home is sensitive to polluted air and where to stay on bad days.

Frequently asked questions

Does Sweden have a national air quality index?

Yes. SMHI publishes a six-level index for monitoring stations, developed by the European Environment Agency ¹.

Is the index value final?

No. It uses preliminary hourly values that may later be adjusted or removed after quality checks ¹.

What should I do if the VMA siren sounds?

Whatever the cause, go indoors, close windows and doors, switch off ventilation if you can, and listen to P4 ³.

Is Swedish air clean by WHO standards?

Fine particles are close to the WHO guideline, at about 6 µg/m³ against 5 µg/m³ as a city median ⁴⁶.