Those who endured last year's heat, cold, rain, snow and drought may not believe it, but Washington's weather in 1978 averaged out at just about normal, according to year-end figures from the National Weather Service.

The funny numbers stem from one of those statistical quirks in which the extremes on either side of a midline balance each other out, leaving a set of averages that are nothing short of blah.

Thus, despite the pounding snows of February, the record heat of August and the drought conditions of last fall, the city's official precipitation totals and temperature averages for the year came very close to normal.

Precipitation for the year totaled 39.56 inches, only 0.67 inches more than the long term average of 38.89 inches hereabouts, weather service figures show.

The temperature for the year averaged 58.1 degrees, only 0.8 degrees warmer than the long-term average of 57.3 degrees.

But these figures mask wild fluctuations in temperature and rainfall throughout the year. In the first two months alone, precipitation totals ranged from 7.11 inches in January to a mere 42 inches in February. The summer months were bountiful in rain, but the fall extremely dry.

Monthly temperatures bounced from a subfreezing average of 31.4 degrees in February (almost 6 degrees below the normal of 37.3 degrees) to 81.3 defrees in August, 4.2 degrees above the normal of 77.1 degrees and the hottest August in the 106-year-old record books of the weather service.

While montuly averages ran to extremes, there were few individual days of extreme hear or cold. During the summer, the temperature hit 90 degrees or hgher on 39 days, very near the annual average of 37. Likewise, in the winter, the temperature fell to the freezing mark of 32 degrees or lower on 76 days, only one more than the average of 75.

The first freezing temperature in the fall did not occur until Dec. 10, the lastest date on record.

The Potomac River, which provides much of the drinking water for te area, ended the year well above its average flow level, swollen by heavy rains in the final days of December.

For the year as a whole, the river averaed 9.5 billion gallons a day at Little Falls, or about 61 percent above the normal annual flow of 5.9 billion gallons a day, according to the U.S. Geological Survey.

the daily flow level fluctuated erratically during the year, ranging from a high of 90.4 billion gallons on March 16 to a low of 1.9 billion gallons on Nov. 9 during the area's prolonged drought last fall. CAPTION:

Picture 1, Early in January a year ago, snow was piling up on the benches in Lafayette Park as boundled-up pedestrians went trudging by. By James M. Thresher -- The Washington Post