U.S. natural gas futures for September delivery closed at $2.776 per million British thermal units on Nymex, up 8.6 cents or 3.2 percent, as forecasts of sustained triple-digit heat across Texas signal elevated power demand.

AccuWeather projects average highs of 100 degrees Fahrenheit in Houston from Aug. 20-23, roughly 5 degrees above the seasonal norm. The heat is expected to spike air-conditioning load on the Electric Reliability Council of Texas grid at a time when wind generation subsides, forcing greater reliance on gas-fired generators.

Eli Rubin, senior energy analyst at EBW Analytics Group, said peak load on the ERCOT system could establish a new record this week. The compression of renewable supply during peak demand windows narrows the operational margin and forces marginal gas generation into the stack.

For fixed-income markets, sustained pressure on natural gas prices filters directly into near-term inflation expectations. Any persistent energy commodity rally sharpens the Fed's focus on price stability in rate-setting deliberations. A spike in forward gas curves during supply tightness on the grid would reinforce market skepticism about near-term rate cuts and compress long-duration bond valuations.