The onset of fall weather and demand uncertainty weighed down weekly cash prices.

NGI’s Weekly Spot Gas National Avg. for the Sept. 8-11 period fell 22.5 cents to $1.890.

Cooler conditions took hold during the week, particularly on Monday, when an early snowstorm blew into the Rocky Mountains and sent cool shots across much of the nation’s midsection. This offset continued extreme heat farther west.

The National Weather Service noted that intense heat continued in the Southwest and California during the week, but temperatures dropped to winter-like levels across the Rockies, and the cold front gradually pushed east, bringing comfortable temperatures and chilly rains to swaths of the central United States, minimizing cooling demand.

As the trading week closed, Waha...