Drought is the least spectacular but often the most persistent natural hazard to affect Marlborough. It develops relatively slowly, is long lasting and often widely dispersed in extent. Drought may be defined in many different ways. Easiest of all is by applying the concept of lack of rainfall. If agriculture is the primary concern then soil moisture deficit might be a more appropriate measure. Drought costs the community through lost economic productivity and social stress, while the environmental consequences often go unmeasured.
Extreme drought conditions can also create a high risk environment for fire, even though the fire itself may not arise through natural causes. An example of this occurred in 2000 when Marlborough recorded the highest ever national fire index level. The extreme drought conditions at the time culminated in the Boxing Day fires near Ward and on the Wither Hills near Blenheim. Some 600 hectares of farmland were burnt in the Ward fire. The Wither Hills fire was much more extensive, burning some 6100 hectares and, at the time, was the largest grass fire recorded in New Zealand for the preceding 17 years.