Saint Johns, AZ Climate

Climate Insight: Saint Johns, AZ

Saint Johns, Arizona runs an annual average of 55°F, ranging from a mean daily high of 71°F to a mean daily low of 38°F, per NOAA's 1991–2020 climate normals. July is typically the warmest month of the year, while December is the coldest. Drawn from station USC00027435, these thirty-year averages smooth out year-to-year swings into a baseline for what a typical month looks like here.

Rainfall (and snow, where it falls) shapes day-to-day life here as much as temperature does. Saint Johns sees about 9.4 inches of precipitation a year, with 6.2 inches typically falling as snow. The frost-free season averages 165 days, which directly shapes the planting calendar and growing potential for the area, with the last spring freeze near May 2 and the first fall freeze near October 14. On the energy side, 4,638 heating degree days and 890 cooling degree days tell the story of how often furnaces and air conditioners run during a normal year.

On PlainClimate's composite comfort index, Saint Johns scores 44/100 (Moderate), a blended measure that weighs temperature mildness, precipitation moderation, and extreme-weather frequency against one another. Use the monthly tables above to plan around specific windows, shoulder seasons for mild highs and lows, peak summer for July-driven heat, or deep winter for December-driven cold. All figures here are thirty-year averages: any single year may run warmer, wetter, drier, or cooler than the normal, so treat them as planning guidance rather than forecasts.