Annual air quality map

Wondering what the outdoor air quality is like in your residential area? Are you moving? Our annual nitrogen dioxide (NO2) concentration map of air quality allows you to take a closer look at the impact of traffic exhaust gases on the air quality in your residential area at breathing height on an annual basis. The concentrations of fine particles (PM2.5) reflect not only local traffic and wood burning emissions but also particles transported from outside the country’s borders.

Are you an urban planner? You can check on the map how traffic exhaust gases affect the air quality of planned sites on an annual basis in the present situation. The fine particle map shows the impact of local traffic, wood burning emissions, and particles transported from outside the country’s borders on air quality.

However, please note:

  • The effects of, for example, machinery or street dust on the air quality are not yet shown on this map.
  • The impact of ships is included and it is indicative.
  • The annual map describes the air quality outside. The margin of error of the results is higher on the walls of buildings, and inside buildings the results are only rough estimates.
  • The annual map is indicative, even though you are able to see the results very close up. The concentrations have been compared with measurements and they are for the most part quite accurate. However, in some places, the annual map significantly underestimates concentrations. For example, new areas being built lack streets and buildings, and the traffic volume data is incomplete. Concentrations may be underestimated in congested areas. In addition, detailed terrain features, such as bridges or noise barriers, are not taken into account in the model. 

       

The air quality map is based on modelling that combines, among other things, the information about air quality monitoring, weather, emissions, land use and long-range transport of air pollutants from outside the country’s borders.

If you wish, you can save the annual air quality map as a quick link: ilmanlaatuvuosikartta.hsy.fi
In this case, only the annual air quality map becomes visible, without any texts or instructions. If the map does not load properly, you should clear your browser cache and try again.

How do I use and interpret the annual concentration map of air quality?

The annual air quality map currently shows the modelled nitrogen dioxide concentrations from 2022, 2023 and 2024. Nitrogen dioxide mostly comes from traffic exhaust gasesand fine particles from particles transported from outside the country’s borders, local traffic, and wood burning.

  • By default, the annual map shows the annual average.
  • The colour scale on the right side of the annual map shows the numerical value of the concentration at the changing point of the colour.
  • You may view the annual map from further away or close up by clicking on the plus (+) or minus (-) sign in the top left corner of the air quality map.
  • The buildings become visible when you zoom in. Buildings are not visible if the map of the entire area is opened.
  • When the buildings are visible, clicking on a specific location will display the annual average for that location. In addition, you can see how concentrations vary in different months as well as at different times on weekdays and weekends.
  • In addition to the annual concentration, you can select the average concentrations for winter (December–February), spring (March–May), summer (June–August) or autumn (September–November) under ‘Whole year’. Click a specific location on the seasonal map to see the average concentration for that time of year.
  • Under information, there is a link to these instructions and pages with tips on air quality for residents and urban planners.
  • You can download the map for yourself in geographic information format from the buttons in the top corner. Please contact us if you use the data in another service or application.
  • The map works best with the Chrome browser.

On the right side of the map, there is a colour bar indicating the air quality. The colour green refers to good air quality and the closer you get to red, the poorer the air quality is. Also, the lower the concentration, the better the air quality. 

The map shows the nitrogen dioxide concentrations in exhaust gases from car traffic. If their concentrations are high, then the concentrations of fine particles caused by traffic are also elevated.

In addition to exhaust gases, car traffic causes street dust and noise as well.

Additionally, the map shows the concentrations of fine particles. In the Helsinki metropolitan area, the concentrations of fine particles in the outdoor air are affected by emissions from traffic and wood burning. Furthermore, a significant amount of fine particles is transported to the metropolitan area from outside the country’s borders. Due to their small size, fine particles remain in the air for a long time and can be carried by air currents for thousands of kilometers. Long-range transport accounts for more than half of the fine particle concentrations on average, even in the busy traffic areas of the metropolitan area.