| Sulphur dioxide concentrations and exceedances 2005–13 | Environmental Reporting | Ministry for the Environment | Creative Commons Attribution 3.0 New Zealand | Table | Table | 2809 | 32 | ||
| Sulphur dioxide concentrations, 2008–17 | Environmental Reporting | Ministry for the Environment | Creative Commons Attribution 4.0 International | Table | Table | 2298 | 30 |