weather in prosser washington
Prosser 10 Day Weather. 1  Friday:The Prosser forecast for Mar 24 is 47 degrees and Light rain. There is 83 percentage chance of rain and 6 mph winds from the South. 2  Saturday:The Prosser forecast for Mar 25 is 53 degrees and Partly cloudy. There is 46 percentage chance of rain and 17 mph winds from the West-Southwest.