A cold front in summer? We do get them occasionally in Northern California, though not often. Usually from May-October a strong high pressure ridge keeps storms and the jet stream away from Nor Cal and the Sierra Nevada. Much different than say the Rockies that can tap into the moisture form the Pacific Northwest. Sure we get out share of afternoon thunderstorms, but not a two day cold rain event. When it does happen you need to be out on the water. Clouds and rain bring out the bugs, and trout love to feed in low light conditions. The dry fly fishing and streamer fishing can be epic during a summer rain event. Whatever you do go fish. Don’t cancel on your guide, man up and put the rain jacket on. I’ve been dry fly fishing for the last couple days with guests. Green drakes yesterday, pale mornings today. The rain will be short lived, 90’s by the end of the week.