Porthill, ID Climate

Climate Insight: Porthill, ID

Based on station USC00107264 feeding NOAA's 1991–2020 climate normals, Porthill, Idaho averages 47°F a year, ranging from a mean daily high of 60°F to a mean daily low of 35°F. July is typically the warmest month of the year, while January is the coldest. Because these figures are thirty-year averages rather than any single year's readings, they describe the typical month, not a forecast for it.

Rainfall (and snow, where it falls) shapes day-to-day life here as much as temperature does. Porthill sees about 21.5 inches of precipitation a year, predominantly as rainfall. The frost-free season averages 149 days, which directly shapes the planting calendar and growing potential for the area, with the last spring freeze near May 4 and the first fall freeze near September 30. On the energy side, 6,757 heating degree days and 333 cooling degree days tell the story of how often furnaces and air conditioners run during a normal year.

On PlainClimate's composite comfort index, Porthill scores 64/100 (Good), 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, July-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.