To calculate the difference in temperature, you need to subtract the initial temperature from the final temperature. In this case, the initial temperature is -4 degrees Fahrenheit, and the final temperature is -12 degrees Fahrenheit. To find the difference, subtract the initial temperature from the final temperature: -12 - (-4) = -12 + 4 = -8 degrees Fahrenheit. So, the temperature dropped 8 degrees Fahrenheit.