As per Wikipedia: "Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and other meteorlogical element measurements in a given region over long periods of time....."
As per the Illinois State Climatological Office (ISCO) there are three (3) influences that will affect a climate: 1) topography, 2) urban areas, and 3) bodies of water.
Oroville, WA, is located in the southern part of a high desert region. Osoyoos, BC, Canada, is just 6 miles north and is the warmest place in Canada. And Lake Osoyoos, some 18 miles long has 1/3 of the lake in the United States; 2/3 in British Columbia. The water level (ONLY) is regulated by the International Joint Commission. Water quality issues are being addressed.
Oroville is between mountain ranges for the most part. The Cascades to the west and the Rockies way to the east. Thus a lot of weather skips over us to the adjoining regions.
Normal storm systems come from the west or northwest. Because the wind direction in these low pressure systems is counter-clock-wise, fairly frequently winds for storms come up through northern California and Oregon through central into northeastern Washington State. Thus, the prevailing winds come mainly from the south, but a fair amount comes from the north as well. Most storms have a major affect on Spokane more than Oroville.
During the summer, precipitation comes mainly from "thunder" storms that blow through or major low pressures that come from the coastal area.
Torrential Rain - 3 inches or more within a 24 hour period.