Indicators based on climatology enable people to describe drought in a consistent way across different times and places. These indicators combine variables such as precipitation and temperature. Some indicators represent drought within specific intervals of time. Caveat: Climate-based drought indicators do not reflect changes in how droughts affect us. Increasing population density or intensive cultivation may make the effects of drought worse. Conversely, urban water users may be buffered from all but the worst supply fluctuations.

For a detailed comparison of drought indices, please refer to "Drought Indices".