Natural-gas futures climbed by almost 12% on Monday, cutting their loss for the month, with volatility high as traders continued to keep an eye on U.S. supply levels for the winter heating season. December natural gas NGZ22, +11.22% rose 67 cents, or nearly 11.8%, to settle at $6.355 per million British thermal units on the New York Mercantile Exchange, down 6.1% for the month, according to Dow Jones Market Data. Meanwhile, oil finished lower Monday after China’s factory activity weakened in October, feeding expectations for a decline in energy demand. But prices still posted a climb for October, supported by tight global supplies and a decision by the Organization of the Petroleum Exporting Countries and their allies in early October to cut production in November. December West Texas Intermediate crude CLZ22, -2.04% fell $1.37, or 1.6%, to settle at $86.53 a barrel, up 8.9% for the month.