Average Temperatures for Philadelphia. Philadelphia's coldest month is January when the average temperature overnight is 25.5Â°F. In July, the warmest month, the average day time temperature rises to 85.5Â°F.The driest month in Philadelphia is February with 2.74 inches of precipitation, and with 4.39 inches July is the wettest month.n July, the warmest month, the average day time temperature rises to 85.5Â°F. The driest month in Philadelphia is February with 2.74 inches of precipitation, and with 4.39 inches July is the wettest month.
1 A data set has three quartiles: the lower quartile, the median of the data set, and the upper quartile. 2  Median: The median divides a data set into two equal parts. 3  Lower quartile: Median of the lower half of the data. 4  Upper quartile: Median of the upper half of the data.
Definition. One of the three points that divide a range of data or population into four equal parts. The first quartile (also called the lower quartile) is the number below which lies the 25 percent of the bottom data.