The average annual concentration of SO2 outside of residential estates in the region of Stuttgart is 25 to more than 35 µg/m3 and the short-term concentration 130 to more than 170 µg/m3. On the contrary, the analysis also shows that for many areas in Southwest Germany the limit value of 25 µg/m3 for sensitive plants, determined by the International Union of Forest Research Organizations, is met on average or even stayed below. The highest values (> 35 µg/m3) are registered especially in the Neckar and Upper Rhine region. The limit value for the short-term concentration at extreme locations (75 µg/m3) is exceeded nearly everywhere. Pollution increases rapidly towards lower areas (the Neckar basin and the Rhine rift valley).