Atenolol and chlorthalidone combination is used to treat high blood pressure (hypertension). High blood pressure adds to the workload of the heart and arteries. If it continues for a long time, the heart and arteries may not function properly.
San Marcos Average Weather. 1  The highest monthly average temperature in San Marcos for August is 70 degrees. 2  The lowest monthly average temperature in San Marcos for January is 55 degrees. 3  The most monthly precipitation in San Marcos occurs in January with 2.3 inches.  The air quality index in San Marcos is 22% worse than the national average.
San Marcos. San Marcos is located about 5 miles inland from the ocean and about 30 miles from downtown San Diego. The community covers about 24 square miles and, as of the 2000 census, had about 55,000 residents and almost 18,700 household units. Census data also indicate a fairly diverse population.