I got this image while checking weather data for a city in North India using Mathematica's Wolfram Alpha query
I noticed one feature in the graph which i could not explain . Why does the encircled part 'A' which denotes sunrise has slightly higher slope as compared to encircled part 'B' which denotes sunset !
I also checked the graph for summer month and the pattern was exactly opposite
Am i interpreting the data wrong or is it so that sun achieves its highest intensity during the day faster in winter months than in summers ? What could be the reason behind this ?