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, CA Profile. San Marcos, CA, population 80,699, is located in California's San Diego county, about 4.9 miles from Escondido and 12.9 miles from Oceanside. Through the 90's San Marcos's population has grown by about 41%. It is estimated that in the first 5 years of the past decade the population of San Marcos has grown by about 34%.