I usually dont know until i go. If its really windy I'll try to fish holes on the creek that have good cover from the wind or holes that require shorter cast and drifts. High sticking is my favorite way to fish in brutal winds. You can usually count on summer being windy in the afternoons. Wintertime it all deponds on our storm sets and how the winds will blow before and after the storms pass. I live in Vacaville and usaully the winds are similiar but not always sometimes it s better on the creek and sometomes not.
I use weather.com for "Winters CA", with the "hourly" option. This will give you the hour by hour temp and wind speed and direction. It's better than having no information at all. However, because Putah is in a valley surrounded by hills, the wind forecast is incorrect a good percentage of the time. I think that the hills can either block the wind or increase it due to a "funnel effect". I can't tell you the number of times I was expecting light winds, but got stiff winds when I got to the stream. Once in a while, it works in reverse; I expect stiff winds and I get calmer conditions.
I also look in the local newspaper for the forecasts for Napa and Sacramento. They always contain wind forecast (e.g. 5-10 mph). By looking at both Napa and Sacramento, I can get an idea of what the wind will be like. A word of caution: if the forecast is 5-10 VAR (variable), expect gusty conditions.
I just moved from Vacaville; lived there most of my life. I agree that you just don't know until you make it up there. I go fishing and wakeboarding in the area all the time and you just never know. Sometimes it was perfect in Vacaville, and horrible at the lake...sometimes the opposite.
On the putah creek weather link there is whats pretty much a real time wind gauge takin at browns valley road i think. I have found very acurate. Also tells you in red lettering if there a high wind advisory in the area. Last weekend was pretty windy, Was windy enough that i could hold my backcast at the 12 o'clock position and let my flyline flap like a flag, Wasn't very much fun. Water had enough chop that i may easily have missed some hits.
