Pittsburgh's Golden Triangle on February 20, 2015. Persistent below freezing temperatures caused the waterways to freeze over, with just a narrow open channel for traffic along the Monongahela River. The average daily temperature for the month was 18.3 degrees, making it the second coldest in the city since record keeping began in 1871. The coldest month on record was February 1978, with an average of 18.0 degrees. Photo by Katelyn Allison.