Average gas bill in Illinois
$94a month, on average
$1,122 over the 12 months September 2025 – August 2026 for a typical residential natural gas customer: total spending divided by 4,002,563 customers (2024 count).
In context
- Previous 12 months
- $1,050(+6.9%)
- U.S. average
- $1,023 (+9.7%)
- Gas used per year
- 94.3 Mcf ≈ 977 therms
- Latest price (Aug 2026)
- $21.38/Mcf
- Last winter’s price
- $10.41/Mcf $1.00/therm
17th highest yearly gas bill of 51 states and D.C.
Month by month
The winter months (November–March) made up 68% of the year’s gas spending. The highest bill was $204 in January 2026; the lowest $39 in July 2026.
Show the numbers
| Month | Gas per customer | Price | Average bill |
|---|---|---|---|
| September 2025 | 1.94 Mcf | $21.51/Mcf | $41.70 |
| October 2025 | 3.87 Mcf | $15.45/Mcf | $59.82 |
| November 2025 | 10.05 Mcf | $10.56/Mcf | $106.17 |
| December 2025 | 18.09 Mcf | $9.48/Mcf | $171.46 |
| January 2026 | 21.13 Mcf | $9.65/Mcf | $203.90 |
| February 2026 | 14.08 Mcf | $11.40/Mcf | $160.55 |
| March 2026 | 10.24 Mcf | $12.10/Mcf | $123.90 |
| April 2026 | 5.37 Mcf | $14.29/Mcf | $76.75 |
| May 2026 | 3.82 Mcf | $15.39/Mcf | $58.77 |
| June 2026 | 2.11 Mcf | $19.71/Mcf | $41.66 |
| July 2026 | 1.83 Mcf | $21.04/Mcf | $38.55 |
| August 2026 | 1.81 Mcf | $21.38/Mcf | $38.59 |
Estimate your bill
Why the price per Mcf jumps in summer
EIA’s residential price is total revenue divided by gas delivered. Utilities charge a fixed monthly customer fee, so in summer, when households burn little gas, that fee is spread over a small volume and the price per Mcf looks high ($21.38 in August 2026). The winter price, $10.41 per Mcf for Nov 2025 – Mar 2026, is closer to what each extra unit of heat costs.
Gas or a heat pump in Illinois?
At last winter’s gas price and this year’s electricity rate (19.2¢ per kWh), heat from a 90%-efficient gas furnace costs $11.16 per million Btu and from a heat pump with a seasonal COP of 2.5 about $22.54. Gas is the cheaper heat here at current prices. Compare every fuel in Illinois.
Source and method
U.S. Energy Information Administration: residential natural gas price (series N3010IL3), residential consumption (N3010IL2) and number of residential consumers (NA1501_SIL_8). Average bill = consumption per customer × average price, month by month. EIA withholds some months for some states; the 12-month window above is the latest with every month reported. Page rebuilt November 4, 2026.