Don't know how chilly it gets in Oakdale, CA, this time of year, but if you're riding on summer performance tires, temperature can definitely be a factor as well. When shopping for tires on tirerack.com, with these tires you'll typically note the warning: "Like all summer tires, it is not intended to be driven in near-freezing temperatures, through snow or on ice."
I learned this lesson the hard way going out to grab some take-out. It was cool, low-40s or high 30s, which generally hadn't been a problem for me---I knew to take it a bit easier under such circumstances. This time, however, it started to rain gently shortly after I left home. Cold + Wet + summer performance tires is a REALLY bad combo!
