The cold season lasts 3 or 2 months, from November 20 to February 27, with an average daily high temperature below 73° F. The coldest month of the year in Scottsdale is December, with an average minimum of 45° F and a maximum of 66° F. Scottsdale has maximum temperatures of 100 degrees Fahrenheit most days during the summer. The 100-degree weather generally starts in May and can persist through September.
In some years, even one day in October it reaches 100 degrees. The coldest month in Phoenix is January, when the average temperature during the night is 43.4° F. In July, the warmest month, the average daytime temperature rises to 104.2° F.