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.
Quartiles divide a rank-ordered data set into four equal parts. The values that divide each part are called the first, second, and third quartiles; and they are denoted by Q1, Q2, and Q3, respectively. Note the relationship between quartiles and percentiles. Q1 corresponds to P25, Q2 corresponds to P50, Q3 corresponds to P75. Q2 is the median value in the set.