Effis estimates the damage caused by a wildfire at Dovestone Reservoir, north of the Tintwistle blaze, is about 90 hectares (220 acres).
Derbyshire Fire and Rescue Service said operations resumed on Monday after they were suspended on Sunday due to heavy rainfall, which had created “poor visibility and dangerous conditions” on the moorland.
A spokesperson for the service said: “While this has provided some welcome assistance to crews by helping to dampen vegetation and reduce fire activity in some locations, supporting the significant progress already made by firefighters and partner agencies, work continues to fully extinguish the fire.”
It said crews were working alongside partner organisations to extinguish remaining hotspots, reduce the risk of reignition and bring the fire to a “safe conclusion”.
However, it said the fire remained a major incident due to its “scale, terrain and complexity”.
People have also been warned to stay away from areas affected by the fire, and to avoid using barbecues or starting campfires on moorland.