The natural gas shortage may keep thousands of small factories closed in seven states east of the Mississippi River until the end of the summer, mostly because the pipelines serving those states will take that long to refill near-empty storage fields.

"Getting gas into the pipelines with big storage requirements is going to be a problem we'll have to live with until the end of summer," Federal Power Commissioner John H. Holloman III said yesterday in an interview.

"There's only so much gas that can physically be pushed into those storage fields every day, like only so much water can be forced through a hose," he said.

The Federal Power Commission says natural gas customers drew about 100 billion cubic feet of gas a day from the pipelines in the nation during December and January. Normally, customers draw 57 billion cubic feet a day, meaning the overtaxed pipelines were drawing their excess requirements from storage.

By the time the heating season is over in April, storage fields that last November had 1.7 trillion cubic feet of gas will be down to about 200 billion cubic feet. Pipelines will have to pump 1.5 trillion cubic feet of gas back into the same storage fields to get them ready for the heating season that starts next November.

Holloman said this means that, starting in April, pipelines will be pumping 80 billion cubic feet of gas more each month than they usually do, to restore storage to normal. Only a week ago Holloman had estimated that an extra 40 billion cubic feet would bring back the natural gas storage fields.

Three eastern pipelines face the most critical storage shortage, said Holloman, who identified them as Columbia Gas Transmission Corp., Transcontinental Pipe Line Corp. and Consolidated Gas Supply Corp. These pipelines serve seven states hit hardest by the shortage - Kentucky, West Virginia, North Carolina, Ohio, Pennsylvania, New Jersey and New York.

Pennsylvania and New York are served by all three pipelines. Ohio is the most gas-dependent state in the nation. New Jersey lies at the end of the Transco pipeline, where shortages have been the greatest.

The Commerce Department now estimates gas-caused unemployment in the seven states at 1.1 million and at 890,000 in the four states hit hardest - Ohio, Pennsylvania, New York and New Jersey. Over the weekend, the White House said that layoffs caused by the bad weather and the gas shortage reached a peak of 1.8 million.

Holloman said it it is impossible to estimate how many factories will be closed until the end of the summer, except to say that it could be thousands of small factories employing as few as 25 people.

Some of the shortage was already softened this weeek as emergency gas supplies moved into eastern pipelines under provisions of the Natural Gas Emergency Act signed last Wednesday by President Carter.

The FPC said Monday that 380 million cubic feet a day was flowing under emergency arrangements and another 175 million cubic feet a day was authorized and awaiting completion of connecting pipes.

The Commerce Department's top economist estimated that economic growth the first three months of the year will be cut by $2.5 billion because of the severe winter. The economist, John W. Kendrick, told Association Press that the growth rate will be 2 per cent smaller this year on the basis of first quarter figures.

Around the country, it was 55 degrees colder yesterday in Elkins, W. Va., than in Anchorage. Alaska, where sled dogs were shedding and Eskimo Scouts complained of the 33-degree heat.

It was still so cold and snowy in Buffalo that the weather expert who'd been there for 26 years quit.

"After all this, I just asked myself what am I doing here?" James E. Smith, 56, said yesterday. "This winter was the last straw."