Pontiac, IL Climate

Climate Insight: Pontiac, IL

The NOAA 1991–2020 climate normals describe Pontiac, Illinois as a location with an annual average temperature of 52°F, ranging from a mean daily high of 61°F to a mean daily low of 42°F. July is typically the warmest month of the year, while January is the coldest. These thirty-year averages, computed from station USC00116910, smooth out year-to-year variability and give a baseline expectation for typical conditions in any given month.

Rainfall (and snow, where it falls) shapes day-to-day life here as much as temperature does. Pontiac sees about 37.0 inches of precipitation a year, with 25.1 inches typically falling as snow. The frost-free season averages 191 days, which directly shapes the planting calendar and growing potential for the area, with the last spring freeze near April 16 and the first fall freeze near October 24. On the energy side, 5,840 heating degree days and 1,052 cooling degree days tell the story of how often furnaces and air conditioners run during a normal year.

On PlainClimate's composite comfort index, Pontiac scores 63/100 (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.