Weekly natural gas cash prices gave up ground for the first time in a month, with bears seizing upon elevated supplies and moderately easing weather-driven demand in northern markets.

NGI’s Weekly Spot Gas National Avg. for the July 31-Aug.4 period fell 38.0 cents to $2.505. This followed three consecutive weekly gains that were driven largely by scorching heat that developed first in the Southwest and Texas and then spread to the North and East in the second half of July.

While heat remained unforgiving over large swaths of the West and South, conditions in the past week cooled just enough from the Great Lakes to the Northeast to tamp down national demand. Peak temperatures in those regions dipped into the 80s – down from highs in the 90s in late July.

At the same time,...