U.S. natural gas futures for March climbed more than 5 percent early Monday to their highest level since December 2008 on forecasts for continued cold before paring gains later in the morning.

MDA Weather Services forecast intense cold in the U.S. North-Central over the next five days with another intense cold shot over much of the country over the next six- to 10-days.

Front-month natural gas futures on the New York Mercantile Exchange were up 12.8 cents, or 2.09 percent, to $6.263 per million British thermal units at 8:38 a.m. EST (13:38 GMT).

With the gains Monday morning, the front-month contract was up about 53 percent since the beginning of the year.

Traders however noted the price gains were mostly in the front month and not the balance of the year and prices. They said prices had to rise in the balance of the curve, especially over the summer months, to encourage producers to drill for more gas to help rebuild storage levels after this winter's record draw.

The balance of the year gas strip on the New York Mercantile Exchange settled at $5.01 on Friday. Last week, the strip reached $5.34, the highest level since June 2010. The summer of 2014, meanwhile, is trading at just $4.86.

Inventories of natural gas are 40 percent below last year's levels. The U.S. Energy Information Administration last week reported a 250 billion cubic foot (Bcf) draw from storage marking a record fourth straight week of 200-Bcf plus draws.

Some analysts expect the nation to finish winter heating season at the end of March with less than one trillion cubic feet of gas stored underground, which would mark a more than 10-year low for that period.

Others say utilities will switch to coal for power generation as coal prices remain below $3 on an energy equivalent basis and producers will pump enough gas to replace inventories in time for next winter.

Nuclear plant outages, which create demand for natural gas as a substitute fuel, were at 11,600 megawatts (MW) up from 9,600 MW on Friday. That compares with 16,700 MW a year ago and a five-year average outage rate of 11,400 MW.

The number of rigs drilling for gas in North America rose by five to 342 in the week to February 21, according to oil services firm Baker Hughes.