Population Forecast
5 year Forecast - -0.2%
The current population of the Springfield-Decatur, IL Market is 497,389 as of the January 2026 PopStats estimate. PopStat’s Trend models indicate a 5 year population change of -0.2%, resulting in a Population of 496,191 by January 2031. This percentage change in Population ranks 143rd across STI Markets. The Springfield-Decatur, IL Market currently ranks 147th in overall population, and will rank 147th by January 2031.
High and Low Range - -2.3% to 2.9%
While the summation of mid range 5 year forecasts foresee a change in Population of -0.2% for Springfield-Decatur, IL Market. The forecast high ranges of these forecasts leaves open the possibility for a Population change as high as 2.9% at 511,797. Similarly a population change as low as -2.3% at 486,033 is not without possibility.
Figure 73: Population Trend and Forecast
10 year Projections - -0.5%
By January 2036 we project the Population of the Springfield-Decatur, IL Market to be 495,130 resulting in a change of -0.5% compared to the current Population. This projected percentage change in Population ranks 146th across STI Markets. The Springfield-Decatur, IL Market currently ranks 147th in overall population, and will rank 148th by January 2036.
