I also wonder what to do in July and August?!
There is Ceramique Cafe (The Mall), or ice skating (Villagio/City Center).
The beach in Al Wakra is already too hot after 11 am.
Hopefully Sealine Resort is better (but far away).
The museum is nice for 1 or 2 hours.

If you have more suggestion...please let us know.

Thanks a lot.