Natural gas and oil ended the week with solid gains, with one boosted by forecasts for colder temperatures and the other by signs that U.S. manufacturing is heating up.

The price of natural gas rose 6 cents, or 1.6 percent, to finish at $3.87 per 1,000 cubic feet. It gained nearly 7 percent for the week, boosted mainly by forecasts for cold temperatures in many gas-consuming regions through the end of the month. Jim Ritterbusch, president of energy consultancy Ritterbusch and Associates, said in a note to clients that he expects natural gas to make "a run at the $4 mark early next week" assuming no change in weather forecasts.

The price of oil rose 42 cents to end at $93.45 per barrel. It was up $1.50, or 1.6 percent, for the week on signs of improvement in the U.S. job market and manufacturing sector. On Friday the government said a strong increase in auto output boosted U.S. factory production by a seasonally adjusted 0.8 percent last month.

Brent crude, used to price many kinds of oil imported by U.S. refineries, gained 86 cents to finish at $109.82 per barrel on the ICE Futures exchange in London.

Experts said Brent's rise was due partly to reports of lower oil exports from Iran -- which is enduring sanctions from Western powers because of its nuclear program -- and expectations about aggravated geopolitical tensions in the Middle East related to the upcoming visit to Israel by President Barack Obama.

A weaker dollar was also supporting oil prices, making crude cheaper for traders using other currencies. On Friday the euro was up at $1.3057 from $1.3010 late Thursday.

At the pump, the average price for gas dipped to $3.695 a gallon. That's about 12 cents cheaper than a year ago.

In other energy futures trading on the Nymex:

  • Wholesale gasoline added 2 cents to end at $3.16 a gallon.
  • Heating oil rose 1 cent to finish at $2.94 a gallon.