Ross Dam, WA Climate

Climate Insight: Ross Dam, WA

An annual average temperature of 49°F, ranging from a mean daily high of 57°F to a mean daily low of 41°F is what the NOAA 1991–2020 climate normals report for Ross Dam, Washington. August is typically the warmest month of the year, while January is the coldest. That baseline comes from station USC00457185 and thirty years of averaging, so it reflects a typical month rather than any one year's swings.

Precipitation patterns matter as much as temperature for anyone planning to live, garden, or travel here. Ross Dam receives roughly 60.8 inches of precipitation each year, with 66.7 inches typically falling as snow. The frost-free season averages 216 days, which directly shapes the planting calendar and growing potential for the area, with the last spring freeze near April 8 and the first fall freeze near November 10. For energy use, 6,083 heating degree days and 303 cooling degree days tell the story of how often furnaces and air conditioners run during a normal year.

On PlainClimate's composite comfort index, Ross Dam scores 38/100 (Below Average), a blended measure that weighs temperature mildness, precipitation moderation, and extreme-weather frequency against one another. The monthly tables above turn that into a planning tool: expect the mildest highs and lows in the shoulder seasons, August-driven heat at the peak of summer, and January-driven cold at the depth of winter. Every number here is a thirty-year average, not a forecast, so any given year can and does run warmer, cooler, wetter, or drier than the normal.