Flowers in July

What flowers are in season this time of year and are not ridiculously over-priced?
I am going to florists next week and want to pick out flowers.

PS: My girls are in yellow so if you have any specific ideas that would go well w/ yellow, feel free to suggest stuff.
Thanks!!

roses are in season. My sister had yellow dresses and used yellow roses with a purple flower (don't remember the name). It looked gorgeous together.

I used calla lilies, they held up beautifully in the heat. My florist told me they are great sturdy flowers and he was right.

HTH,
Kelly