The major wine regions of Argentina are located in the western part of the country among the foothills of the Andes Mountains between the Tropic of Capricorn to the north and the 40th parallel south. Most of the regions have a semi-arid desert-like climate with annual rainfall rarely exceeding more than 10 inches (250 mm) a year. In the warmest regions (such as Catamarca, La Rioja, San Juan and the eastern outreaches of Mendoza), summer temperatures during the growing season can be very hot during the day with temperatures upwards of 40 °C (104 °F).