The most important thing when leaving your scope set up during the day is to make sure both the OTA and the finderscope are capped at the objective end, and optionally also parked so no direct sunlight can enter the scope or finder during the day (just in case a cap is dislodged).
The sun will fry the insides of the scope finder if it gets in directly. Seen it done. The owner wasn't happy!
So cap it, park it away from the sun and cover it with a tarp/scope cover/bike cover, etc.
Al.