12am: The Klamath, CA forecast for Jan 30 is 54 degrees and Partly cloudy. There is 75 percentage chance of rain and 5 mph winds from the North-Northwest. 3pm: The Klamath, CA forecast for Jan 30 is 53 degrees and Partly cloudy. There is 67 percentage chance of rain and 9 mph winds from the North-Northwest. 6pm: The Klamath, CA forecast for Jan 30 is 49 degrees and Partly cloudy. There is 75 percentage chance of rain and 6 mph winds from the Southwest. 9pm: The Klamath, CA forecast for Jan 30 is 46 degrees and Partly cloudy. There is 84 percentage chance of rain and 2 mph winds from the North-Northeast. Klamath 5 Day Weather. Tuesday: The Klamath forecast for Jan 30 is 54