Identify the cause of temperature fluctuations recorded in both New York and Los Angeles

In New York City, weather observations have been taken in Central Park dating back to 1868. In the 150 years of records the city’s temperature extremes span 121 degrees ranging from a high of 106 on July 9, 1936 to a low of minus 15 on February 9, 1934. In Los Angeles temperatures have been taken at a downtown location since 1877 and extremes there range from a high of 113 on September 27, 2010 to a low of 28 degrees recorded on three occasions, most recently January 4, 1949, an 85-degreee range.

Explanation:

'm pretty sure that's the answer to your question.