This outfit looks like it would be great for a balmy summer day (minus the cardigan). Usually I drag a my favorite cardigan around with me anyway (a gray Mr. Rogers cardigan from Alternative Apparel) regardless of the temperature. That way my outfit can go from day to night (or outside to A/C) easily.
I really like the AE cardigan (shown in the picture above). It has a nautical feel and navy blue goes with everything. However, nothing beats my favorite cardigan. You can still buy my favorite cardigan here.