I will be in siesta key FL in the end of July. I will be staying on a canal near the beach. How is the surf fishing? What could I catch in canal backing up to the house? Would a charter be a good option? If so what charter? Thank you!

 

I've never fished the surf of Florida's Gulf Coast, but this I can tell you.

JULY marks the peak or near peak month of several saltwater species in Florida:

> Tarpon

> Red Drum (Better known as redfish)

> Gray Snapper

> Blacktip Shark (An edible shark known for aerial acrobatics)

> Tripletail (A saltwater delicacy, that hangs around buoys & objects)

 

(I know nothing about guides or charters, but that's easily obtained)

 

Roger

 

There are some fishing piers right by the park that runs under the bridge. You can catch a bunch of stuff when the bait is running thru there. 
As far as the canals, in my experience, that water has a hard time getting out of there and tends to not be very oxygenated and stagnant. You can catch a sail cat or hard head cat nearly every cast I assume and sting rays as well. 
 

My vote would be an offshore charter

Have you been to FL in July before?  Weather is a factor. Go out early. Afternoon thunderstorms are more than likely and happen very quickly. Be prepared for hot and very humid weather.  Good luck.