Consumer prices rose 0.5 per cent in November, up from 0.3 per cent rate of August, September and October and biggest one-month rise since June, the Department of Labor reported yesterday.

The November increase was paced by a 0.7 per cent jump in grocery store costs.

At the same time, the Department of Labor said that the purchasing power of an average hour's work decreased 0.2 per cent in November, but remained 0.5 per cent higher than in November, 1976.

The November increase in the consumer price index works out to an annual rate of 6.2 per cent. It puts the increasing cost of living back on the 6 to 7 per cent path on which it has been stuck for the better part of the last three years.

American consumers had a brief respite from heavy inflation in the summer and early fall, mainly because of exceptionally tame behavior on the part of food prices, but also because of moderate increases for nonfood goods like clothing and cars. In recent months, food prices had been rising 0.1 per cent.

Starting in the fall, however, prices at the farm rebounded. Farm product prices jumped 2.4 per cent in October and exploded another 3 per cent in November.

Higher farm prices did not show up at the retail level in October, to the surprise ofmany analysts, and, according to Assistant Treasury Secretary Daniel Brill, even last month's 0.7 per cent rise in grocery store prices was more moderate than he anticipated.

Julius Shiskin, commissioner of labor statistics, said that despite the acceleration in consumer inflation, the 0.5 per cent rise could be interpreted as good news.

"When you consider the rise in food prices and the rise in automobile prices" did not push up the index very much and that services continue to moderate "you'd have to say it was a reasonably good report," Shiskin said.

Services - which range from medical care to transportation to mortgage interest payments - have been slowing steadily since mid-summer. A 0.8 per cent monthly pace in the first seven months of tthe year slowed to 0.5 per cent in August and September and 0.4 per cent in October and November.

But a spokesman for the Council of Econimic Advisers noted that when the various monthly ups and downs of the consumer price index are smoothed out, consumer inflation remains stuck at an underlying rate of about 6 per cent.

The underlying rate of inflation is basically the difference between hourly earnings and hourly production: if there are bigger increases in hourly compensation than in hourly output of goods and services, businesses are forced to raise prices to cover the difference.

The Labor Department's Consumer Pirce Index - which is undergoing a thorough revision - measures the change in price of a selection of goods and services thought to be representatiive of the purchases of the average urban wage earner heading a family of four. There are about 400 items in the current CPI.

The index is not adjusted for seasonal variation, but all of the percentage changes the Labor Department reports are.

The index stood at 185.4 per cent of its 1967 average, which means that a selection of goods and services that cost $10 in 1967 cost $18.54 last month.

Nationally, most food prices showed increases, with beef climbing 2.7 per cent and resh fruits rising 6.3 per cent. Overall grocery store prices rose 0.7 per cent, restaurant prices rose 0.3 per cent and food prices as a whole increased 0.6 per cent.

Non-food goods - such as feul and clothing - rose 0.5 per cent, with new cars leading the way.Fuel oil prices fell 0.8 per cent, the first time they have fallen since early 1976. But the seasonally adjusted decrease occurred only because they did not rise as much as they would otherwise have been expected to. Unadjusted, fuel prices rose 0.9 per cent and they are 12.4 per cent higher than a year ago.

Medical care costs climbed 0.5 per cent, transportation costs rose 0.2 per cent while rent increased 0.7 per cent. The Consumer Price Index, which has been climbing at an annual rate of 4.4 per cent over the last three months, is 6.7 per cent higher than a year ago.