Pobrecito!

Actually, if you are going by a TV or newspaper weather forecast with a single humidity given for the day, that is not a good prediction of what it will be during your ride. To know that you need to know the dew point and current temperature. Then you look up the humidity on a chart that Google will be happy to direct you to. Using one dew point given for the morning hours is usually fairly accurate for the entire day unless big weather changes occur during that time like a rainstorm or front moving through.

Where is your prediction from? The RH forecasts for both LA and Santa Barbara are much lower than that. Depending on the time of day, anywhere from a high of 50% in the early morning to a low of about 11% mid-afternoon.