A fast-developing “flash drought” that threatened crops and helped spark wildfires across the southern United States is showing the first real improvement in weeks, according to a new report on Thursday.

The latest assessment from the National Drought Mitigation Center said more than a quarter of the country’s Southeast was drought-free, an improvement of more than 10 percentage points in a week. As much as 12.7cm (5 inches) of rain from Tropical Storm Nestor helped douse the drought.

Meanwhile, forecasters said additional heavy rains could inundate the region this weekend. More than 100 high schools in at least seven states moved up American football games a day because of a rainy forecast for Friday night.

More than 25 million people are still affected by arid conditions in the Southeast, with much of eastern Alabama, northern Georgia and western South Carolina far too dry.

Georgia officials have asked for water conservation measures in 103 counties and forecasters said ponds, fields and trees are still drying up in the state. Millions more are living in drought-plagued areas in Texas and the Southwest.

But officials lifted a statewide fire alert this week after scattered rains in Alabama, where about 720 fires burned more than 3,300 hectares (8,200 acres) in September and October. Some stream levels are headed up.

An Agriculture Department report showed some crops doing better in South Carolina, although farm conditions across the region are generally poorer than in recent years.