Yep, here in SOCAL I can get buy with my casual wear running shoes (New Balance mostly mesh uppers) all year simply changing socks to deal with temperature variations. 1/4 height coolmax socks during the warm months and the same Smartwool liners and outer socks I wear in my boots during the winter. If rain is in the forecast I may switch to my Vasque Breeze hiking boots and for these I lose the liners because they can't handle that extra layer.