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 tell us about the spread of a data set by breaking the data set into quarters, just like the median breaks it in half. For example, consider the marks of the 100 students below, which have been ordered from the lowest to the highest scores, and the quartiles highlighted in red.