In California, every driver is required to exercise reasonable care based on the roadway conditions. If another driver loses control of their vehicle and causes a collision with yours, such as a rear-end accident, icy or snow-covered roads are generally not a valid legal defense. They may still be held responsible for the damage to your vehicle and your injuries. An experienced car accident attorney can evaluate the circumstances of the crash and determine whether the other driver's negligence contributed to the collision.
Remember, the measuring tool for this "due reasonable care." Thus, if an accident happens due to icy road conditions because another driver lost control, more likely than not, there was a negligent reason from the other driver for this happening. Such as unsafe speed or an unsafe turing movement. In San Diego, the freezing temperatures are not as common as compared to other parts of the state. However, it does dip into freezing on occasion especially in the mountains and back parts of San Diego County near Julian.