For joggers, walkers and just about everybody else, the month of October was an unalloyed delight. The temperatures, the breezes, the autumn colors met our most demanding specifications.

But the trade-off for all that sunshine was a scarcity of rain that left wooded areas tinder dry and sent both the Potomac River and the surrounding ground water below normal levels.

Only 1.16 inches of rain fell at Washington National Airport, the National Weather Service official measuring point for the area. The rain, which fell on eight widely scattered days, was 1.5 inches below the normal level of 2.66 inches for October.

As a result, the Potomac River reversed its "wet" trend during the summer and fell to an average flow rate of 1.5 billion gallons a day at Little Falls, or about 85 percent of the normal October flow of 1.8 billion gallons a day, according to the U.S. Geological Survey. It was the lowest October flow since 1979.

Also, for the first time since October 1977, ground water levels fell below normal, the survey said. At the end of the month, ground water at a key observation well stood at 13.3 feet below the land surface, 1 feet below the long-term average, according to survey hydrologist Myron Lyn.

On the plus side, the National Weather Service reported that the sun shone during 70 percent of the daylight hours in October, well above the normal of 60 percent.

"We had copious sunshine,"said Weather Service observer Don Marrier at National Airport, with 14 of the month's 31 days classified as "clear" (zero to 30 percent of the sky covered by clouds) and only eight days classified as cloudy (80 to 100 percent cloud cover.)

"Every single day, including the ones with rain, had some sunshine," Marrier said. Five days were 100 percent cloud free, he daid, and several others were 95 to 99 percent cloud free.

The temperature for the month averaged 59.4 degrees, only .4 degrees below the normal of 59.9, degrees, Marrier said. The lowest reading was 40 degrees on Oct. 9 and 25. The highest was 85 degrees on the 23rd, tying the record for that day. A high of 82 degrees on Oct. 26 also tied the record high for that day, Marrier said.