Hot weather riding is always easier if you have less overall coverage and high levels of moisture control. Plus, many athletes prefer the feel of a tank top over a conventional jersey for less obstruction and endless airflow. Louis Garneau's Women's Comp Tank is a cycling jersey made precisely for this scenario. You still have all the great wicking, flatlock seams to eliminate hot spots, and 2 easy-to-reach back pockets for all your gear, but in addition, you have a nice, streamlined, cool tank with a pro-fit and some awesome UV protection.
2 angled back pockets are easy to access
Multimedia pocket allows for headphone wires to be channeled inside the jersey
Flatlock seams eliminate hot spots and chafing
Comfort designed armholes and neck accomodate full range of motion
Front and back reflective accents enhance visibility