Humberhead Peatlands nature reserve near Doncaster will close to visitors on Thursday and Friday because exceptionally high temperatures and dry conditions have created an extreme wildfire risk. The decision is intended to protect visitors and a nationally important wetland and peat-bog habitat, where fires can spread underground and cause lasting environmental damage.

Reserve manager Julian Small said this was only the second time he knew the site had reached the top level of the Met Office Fire Severity Index. A small area of smouldering peat, probably caused by a discarded cigarette, was found in July; the reserve has also experienced fires linked to barbecues and cigarettes. Officials stressed that most English wildfires are started by people, while disposable barbecues are particularly hazardous because they can ignite peat beneath the surface; further closures may follow if conditions do not improve.