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, California. San Marcos is a city in the North County region of San Diego County in the U.S. state of California. As of the 2010 census, the city's population was 83,781. It is the site of California State University San Marcos.