I wonder why the number of featured questions increased nowadays. It was around $30$ before and nowadays above $50$.
The increase in the number of featured questions is roughly proportional to the increase in the total number of questions asked. The number of Questions Asked by Day indeed doubled in recent months:
The chart shows overall growth influenced by season: the number of questions is lower during Northern Hemisphere summers and winter holidays.
in some months the number of user in mse was not doubled i guess..
Since many (most?) questions are asked by relatively new users, it is more appropriate to compare the number of new questions to the number of new users. Which follows roughly the same trend, with very strong spikes during days when math.se was referred to on some more popular website. New users per day: