Merced has a semi-arid climate, featuring very hot, dry summers and mild, wet winters. Average January temperatures are a maximum of 55.0 °F and a minimum of 36.0 °F. Average July temperatures are a maximum of 97.1 °F and a minimum of 60.9 °F. There are an average of 98.7 days with highs of 90 °F (32 °C) or higher and an average of 33.6 days with lows of 32 °F (0 °C) or lower. The record highest temperature of 114 °F (46 °C) was recorded on July 24, 1902, and August 8, 1905. The record lowest temperature of 13 °F was recorded on January 13, 2007.
Most of the rainfall occurs during the winter and averages 12.21 inches (310 mm) annually. There are an average of 48 days annually with measurable precipitation. The wettest year was 1998 with 21.66 inches (550 mm) and the driest year was 1947 with 5.50 inches (140 mm). The most rainfall in one month was 8.00 inches (203 mm) in January 1909. The most rainfall in 24 hours was 2.20 inches (56 mm), which occurred on January 30, 1911, and March 9, 1911. Although snow is relatively rare in Merced, averaging only 0.6 inches (1.5 cm) annually, the city’s proximity to the Sierra Nevada has resulted in some instances of remarkably heavy snowfall. The record 24-hour snowfall was 13.9 inches (35 cm) on February 16, 1946. The most snowfall in one month was 39.0 inches (99 cm) in December 1906.