Gas prices for six of Illinois’ 9 major utilities are elevated, compared with a year ago, led by Liberty Utilities, which is charging a supply price that is about 157 percent higher; MidAmerican Energy, which is charging a price that is about 52 percent higher; and Nicor Gas, with a price about 41 percent higher, according to CUB’s review of September gas prices.
Gas prices have been on the rise, with colder-than-normal weather last winter and record gas exports (meaning profit-hungry companies sending gas outside the United States) increasing demand and tightening supply earlier this year. The Energy Information Administration, the statistical arm of the Department of Energy, said it expects gas prices to be generally lower than earlier forecasts–but the EIA adds “tighter market balances” are predicted to cause “gradually increasing prices through the end of 2026.”
Gas utilities file supply prices–called the Purchased Gas Adjustment (PGA)–each month with the Illinois Commerce Commission (ICC). Here’s what CUB uncovered in our review of prices in September.
- In a bit of good news, compared with August, seven utilities have lower rates: Consumers Gas (about 2 percent lower), Illinois Gas (about 19 percent lower), Liberty Utilities (about 26 percent), Mt. Carmel (about 16 percent), Nicor Gas (about 14 percent), North Shore Gas (about 5 percent), and Peoples Gas (about 30 percent). Two charged prices that were higher: Ameren Illinois (about 8 percent higher) and MidAmerican (about 3 percent higher).
- Compared with September 2024, this month’s prices were higher for six utilities, ranging from about 5 percent higher for Peoples Gas to about 157 percent higher for Liberty Utilities. Three utilities were less than last September: Ameren Gas (about 12 percent lower), Illinois Gas (about 6 percent), and Mt. Carmel (about 32 percent).
September Gas Prices
Ameren Illinois– 46.25 cents per therm (DOWN about 12 percent from September 2024)
Consumers Gas– 53.13 cents per therm (UP about 28 percent from September 2024)
Illinois Gas– 41.62 cents per therm (DOWN about 6.5 percent from September 2024)
Liberty Utilities– 49.45 cents per therm (UP about 157 percent from September 2024)
MidAmerican Energy– 59.23 cents per therm (UP about 52 percent from September 2024)
Mt. Carmel– 33.53 cents per therm (DOWN about 32 percent from September 2024)
Nicor Gas– 45.00 cents per therm (UP about 41 percent from September 2024)
North Shore Gas– 34.17 cents per therm (UP about 15 percent from September 2024)
Peoples Gas– 30.05 cents per therm (UP about 5 percent from September 2024)
Note: Your utility is determined by where you live, so you cannot switch from one utility to another. Under Illinois law, gas utilities are not allowed to profit off supply prices—they pass those costs from gas producers and marketers onto customers with no markup. State regulators annually review the utilities’ gas-management procedures to evaluate whether the companies did a reasonable job with their gas purchases, given market conditions, to hold down costs for consumers as much as possible. Regulators can order refunds, although that is rare.
A few tips from CUB:
- Keep the lines of communication open with your utility. If you are having trouble affording your gas bills, it is vital that you contact your utility. Ask if you qualify for any energy assistance programs; see if you can set up a plan that gives you more time to pay off your bills; and inquire about no or low-cost energy efficiency programs the company offers.
- Practice energy efficiency. For tips and information about helpful energy efficiency programs offered by your utility, visit CUB’s Clean Energy page.
- Beware of alternative supplier rip-offs. If a deal seems too good to be true, there’s a good chance it is. If the utility supply price increases, remember that it’s due to market factors that also will increase alternative supplier prices. As volatile as gas utility prices are, your best bet for gas supply is likely with your utility and not with an alternative supplier. Read our tips. (Note: Only consumers in Northern Illinois have gas choice.)
- More helpful resources:
- CUB’s Gas page
- Historical gas prices
- CUB’s gas-price reports from 2024: January, February, March, April, May, June, July, August, September, October, November and December. And 2025: January, February, March, April, May, June, July and August.
- If you can, consider moving away from gas: Visit our electrification page and order CUB’s free Better Heat Guide to learn how to make the transition to more efficient appliances, like electric heat pumps and induction stove tops.
