Duncan, OK Climate

Climate Insight: Duncan, OK

Based on station USC00342660 feeding NOAA's 1991–2020 climate normals, Duncan, Oklahoma averages 62°F a year, ranging from a mean daily high of 73°F to a mean daily low of 50°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. Duncan sees about 37.1 inches of precipitation a year, with 2.8 inches typically falling as snow. The frost-free season averages 227 days, which directly shapes the planting calendar and growing potential for the area, with the last spring freeze near March 25 and the first fall freeze near November 7. On the energy side, 3,203 heating degree days and 2,091 cooling degree days tell the story of how often furnaces and air conditioners run during a normal year.

On PlainClimate's composite comfort index, Duncan scores 93/100 (Excellent), a blended measure that weighs temperature mildness, precipitation moderation, and extreme-weather frequency against one another. For planning purposes, look to the monthly tables above: shoulder seasons bring the mildest highs and lows, summer brings July-driven heat, and deep winter brings January-driven cold. Treat every figure here as a thirty-year average rather than a forecast - individual years routinely run warmer, cooler, wetter, or drier than the normal.