Sarajevo's air in 3D, hour by hour.
The "Digital Sarajevo" project turns official sensor readings and satellite images into a live 3D map of the city's air, with a three-month forecast and the measures that would clean it.
Terrain, buildings and station values are real. The coloured smog haze between stations is an estimate.
From sensor to your screen in four steps
The air right now
Source: hourly data from FHMZ BiH and Canton Sarajevo stations via the EEA Air Quality Download Service (CC BY 4.0).
How accurate are the forecasts?
We ran each forecast as if it were 10 November 2023, 2024 and 2025, then compared it with what the stations measured afterwards. One row per pollutant, all stations together.
Per station results are under Predictions.
The data can contain errors: EEA values for 2026 are not yet verified, and sensors sometimes fail or measure wrongly. Forecasts and the haze between stations come from computer models, which can be wrong. Do not use this site as your only source for health decisions.
What you can rely on
A lid of warm air traps the smoke in the valley.
Sarajevo sits in a basin surrounded by mountains. On calm winter days, warmer air settles above the colder valley air like a lid. Smoke from stoves, cars and grills can't rise through it, so it piles up where people live.
The valley in 3D
Real terrain from the Copernicus height model, drawn 2.5 times taller for visibility. Drag to rotate. Move the lid to see how much of the city ends up under it.
Labels show the municipalities (općine) of Kanton Sarajevo and neighbouring Istočno Sarajevo, from OpenStreetMap. Orange pins are air stations.
Inversion = daily mean temperature at Bjelašnica (2,067 m) higher than at Sarajevo-Bjelave (630 m), NOAA ISD hourly, winters 2016–2025 (Nov–Feb). PM10 = daily mean at Bjelave, EEA. Days with both records only.
How accurate is the terrain?
Show the peaks and stations we checked
Height model: Copernicus DEM GLO-30. Peaks and rivers: © OpenStreetMap contributors. Station heights: NOAA station lists.
The stronger the lid, the dirtier the air
Winter PM10 at Bjelave against the temperature difference between the mountain and the city. Normally the mountain is about 9 °C colder. The closer the difference is to zero, the stronger the inversion.
Source: PM10 from EEA (CC BY 4.0); temperatures from NOAA NCEI (ISD and GHCN-Daily).
Every winter, every station
Average PM10 by month, all years with data. All seven stations rise sharply from November to February.
Source: hourly data from FHMZ BiH and Canton Sarajevo stations via the EEA Air Quality Download Service (CC BY 4.0).
Traffic and heating each leave a daily rhythm
Winter weekdays at Ilidža, on the valley floor. NO₂ (mostly traffic) climbs with the morning rush hour and peaks again around 17:00–18:00. PM10 is highest from about 19:00 to midnight, when homes heat with stoves.
Source: hourly data from FHMZ BiH and Canton Sarajevo stations via the EEA Air Quality Download Service (CC BY 4.0).
Colder days, dirtier air
Winter PM10 at Bjelave by daily mean temperature. Below freezing, values are two to three times as high as on days above 8 °C.
Source: PM10 from EEA (CC BY 4.0); temperatures from NOAA NCEI (ISD and GHCN-Daily).
Days over the limit, year by year
Number of days with PM10 above 50 µg/m³ (EU daily limit, 35 days per year allowed). From 2030 the EU limit tightens to 45 µg/m³, with at most 18 days over per year. 2026 runs to 9 November.
Source: EEA (CC BY 4.0). Limits: Directive (EU) 2024/2881. Shown only for years with at least 270 valid days. A dot means too little data.
Almost seven years of PM2.5 at Marijin Dvor
Daily PM2.5 since 2020, measured by the US Embassy monitor at Marijin Dvor. The dashed line is the WHO 24-hour guideline of 15 µg/m³.
Source: U.S. Department of State / AirNow (public domain, preliminary data).
Where the city heats up, and where trees cool it.
Satellites measure how hot the ground surface gets on clear summer days. Paved, treeless areas on the valley floor heat up the most.
More green, cooler ground
Surface temperature on the valley floor (below 700 m) by vegetation index. Each step is a 0.1 band of the index.
Sarajevo is getting warmer
Annual mean air temperature at Sarajevo-Bjelave, 1961–2025, and the number of days reaching 30 °C. We cross-checked the hot-day counts against NOAA hourly records for 2017–2024. Those give slightly lower counts, as expected from readings taken every few hours.
Source: NOAA GHCN-Daily, station BKM00014654 Sarajevo. Years with at least 330 days.
Traffic leaves a fingerprint in the data.
No free, open traffic counts exist for Sarajevo. Nitrogen dioxide (NO₂) comes mostly from engines, so it shows when and where traffic matters.
Weekdays and weekends
Winter NO₂ by hour. Weekday mornings are higher, when commuters drive into the city.
Source: hourly data from FHMZ BiH and Canton Sarajevo stations via the EEA Air Quality Download Service (CC BY 4.0).
Spring 2020 was a natural experiment
During the COVID-19 lockdown (16 March to 30 April 2020) traffic dropped. The table compares city stations that have data for both periods with the same dates in 2018–2019.
NO₂ at Bjelave fell by almost half. PM10 did not change at Bjelave but fell by a third at Ilidža, so traffic also matters for particles in some areas. Weather differs between years, so read these numbers as indications.
Source: hourly data from FHMZ BiH and Canton Sarajevo stations via the EEA Air Quality Download Service (CC BY 4.0).
The road network
Road length inside the map area, from OpenStreetMap.
Source: © OpenStreetMap contributors (ODbL), downloaded 9 Nov 2026.
How many bad-air days to expect this winter
For each station, the forecast repeats what the same weeks brought in every past winter since 2016, with recent winters counting more. It knows nothing about this winter's weather. A cold, calm winter will be worse and a mild, windy one better.
The data can contain errors: EEA values for 2026 are not yet verified, and sensors sometimes fail or measure wrongly. Forecasts and the haze between stations come from computer models, which can be wrong. Do not use this site as your only source for health decisions.
The next 92 days
Each square is one day. The darker the square, the more often that time of year brought a bad-air day in past winters.
Month by month
Test results month by month
We ran the same method as if it were 10 November in 2023, 2024 and 2025, and compared the result with what was measured afterwards. Red marks a month whose count fell outside the range.
Daily values in detail
Temperature outlook
Average temperature at Sarajevo-Bjelave on the same dates in the last 10 years, with the coldest and warmest of those years.
Source: NOAA GHCN-Daily, station BKM00014654 Sarajevo. Years with at least 330 days.
Method, in plain words
For each of the next 92 days, we collect the daily averages measured within 7 days of that date in the last five winters. The typical day is the middle value, and the band holds 8 of 10 of them. The chance of a bad-air day is the share of those days that were above the limit. For each month we count the days over the limit in every winter since 2016. The expected number is a weighted average: each year further back counts 80 % as much as the one after it, because the air changes over the years. The range is the one from the last five winters. Tested on the winters 2019–2025, this version cut the error of the monthly average from 17.3 to 16.7 µg/m³; the error in the number of days stayed the same. A daily average needs at least 18 of 24 valid hours. Data: EEA hourly values (verified up to 2025, unverified for 2026) and AirNow daily averages for the US Embassy.
What do these numbers mean?
What would clear the air.
Each measure is linked to what the data on this site shows and to published research. Measures against winter smog come first.
Every number has a source.
This site uses only data from public, open data sources, and names the licence for each source. Every estimate is marked as an estimate.
Data used
How accurate are the forecasts?
We ran each forecast as if it were 10 November 2023, 2024 and 2025, then compared it with what the stations measured afterwards. One row per pollutant, all stations together.
Buildings and their heights
How accurate is the terrain?
Show the peaks and stations we checked
Height model: Copernicus DEM GLO-30. Peaks and rivers: © OpenStreetMap contributors. Station heights: NOAA station lists.
The data can contain errors: EEA values for 2026 are not yet verified, and sensors sometimes fail or measure wrongly. Forecasts and the haze between stations come from computer models, which can be wrong. Do not use this site as your only source for health decisions.
Limits to keep in mind
- 2026 values from EEA are unverified. Official verification happens the following year.
- Times are as published by EEA (station time zone, UTC+1).
- The haze on the 3D map is an estimate between stations.
- Satellites measure the temperature of the ground and roofs. Air temperature can differ.
- Sentinel-5P NO₂ from space has 5×3.5 km pixels, too coarse for streets in this valley, so it is left out for now.
- No open traffic counts exist. Traffic appears here through NO₂ and the road network.
- NOAA hourly records for Bosnia end in August 2025, so the inversion analysis covers 2016–2025.
- The forecast repeats past winters and cannot know this winter's weather.
What is done, and what comes next
This project grows step by step. This list shows what works today and what we are building next. Plans have no fixed dates.
Done
Next
Join us
Want to join us or have an idea for what we should build next? Get in touch at contact@xevorislabs.com.
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We prepare the content of this site carefully but cannot guarantee that it is accurate, complete and current. The data comes from third parties and can contain errors, and forecasts and estimates come from models that can be wrong.
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Texts, design and logo: © 2026 Xevoris Labs. Data, satellite images and maps belong to their owners and are used under the licences listed in the Data and sources tab.
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Last updated: November 2026.
About us and contact
Found an error in the data, have an idea, or want to work together? Get in touch.
- contact@xevorislabs.com
About Xevoris Labs
We explore open data and turn it into clear, checkable insight.
Xevoris Labs turns satellite images, geospatial data and artificial intelligence into insights about how Earth's environment is changing. We look at urban growth, air pollution, vegetation, temperature patterns and environmental forecasts, so that people can see what is happening on our planet and what may happen next. As the first project, we started Digitalno Sarajevo: the air of our city, hour by hour.
The name joins three ideas:
- X
- ExplorationData exploration: digging into open datasets to find what they really show.
- EVO
- EvolutionThe evolution of data: how data grows and changes, and how we use it for better decisions in cities and communities.
- RIS
- Research & Intelligence SystemsResearch and intelligent systems that turn data into forecasts anyone can check.
Why we started
In winter, Sarajevo's air is among the worst in Europe, yet the data that shows it is scattered across agencies, file formats and websites. Most people only see the smog, not the numbers behind it. Xevoris Labs brings that open data together on one map, explains what it means and shows what could change it. Sarajevo is the first project. The same approach will work for other cities.
Our vision
To make data accessible, understandable and useful for forecasts and decisions.