Lowest time of the year for Adsense?

Depends on the type of site, of course, but my traffic (and earnings) always drops during summer. Also, I think advertisers reduce advertising budgets during this time when they know fewer eyes will see the ads.

The good thing about the earnings drop is that it motivates me to add content, improve SEO, and do the things that will continue to pay off after the summer is over.

 

They have more time to play. People get so addicted they can't stop. Thats great.

 

That's a very good attitude you have.
I see that you're on your way to success!