NEW YORK, May 18 (Reuters) - U.S. natural gas futures rose slightly on Monday to their highest level in seven weeks, boosted by forecasters predicting warmer-than-expected weather over the next two weeks and by declining production in recent weeks.

June gas futures on the New York Mercantile Exchange rose 3.9 cents, or 1.3 percent, to $2.999 per million British thermal units, putting the contract on track for its highest closing level since March 27 for the second day in a row.

The London Stock Exchange Group said that average gas production in the mainland United States, which consists of 48 states, has fallen to 109.5 billion cubic feet per day since the beginning of May, from 109.8 billion in April, and from a record monthly high of 110.6 billion in December 2025.

Meteorologists expect the weather to remain generally warmer than normal until June 2nd.