Gas prices for seven of Illinois’ 9 major utilities remained elevated compared with a year ago, led by Liberty Utilities, which is charging a supply price that is about 208 percent higher; Nicor Gas, which is charging a price about 44 percent higher; and Peoples Gas, with a price about 16 percent higher. According to CUB’s monthly review of gas prices, only two utilities were charging less than last August: Ameren Gas (12.9 percent) and Consumers Gas (19.1 percent).
The Energy Information Administration’s Short-term Energy Outlook has forecasted that prices could be elevated into 2026. Colder-than-normal winter weather in the early part of the year as well as record gas exports (meaning profit-hungry companies sending gas outside the U.S.) have helped increase demand.
The impact of elevated prices is less now, but consumers could be in for a more expensive winter.
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 August.
- Compared with last month, seven utilities charged lower rates: Ameren Illinois (about 5.4 percent lower), Consumers Gas (about 21.4 percent), Illinois Gas (about 9.7 percent lower, MidAmerican (2.7 percent), Nicor Gas (3.7 percent), Peoples Gas (12.7 percent) and North Shore Gas (15.4 percent). Two charged prices that were higher: Liberty Utilities (30.5 percent) and Mt. Carmel (about 1 percent).
- Compared with August 2024, this month’s prices were higher for seven utilities, ranging from about 7 percent higher for Illinois Gas to about 208 percent higher for Liberty Utilities. Only two utilities were less than last August: Ameren Gas (12.9 percent) and Consumers Gas (19.1percent).
August Gas Prices
Ameren Illinois–42.70 cents per therm (DOWN about 12.9 percent from August 2024)
Consumers Gas–54.37 cents per therm (DOWN about 19.1 percent from August 2024)
Illinois Gas–51.27 cents per therm (UP about 7 percent from August 2024)
Liberty Utilities–66.90 cents per therm (UP about 208 percent from August 2024)
MidAmerican Energy–57.29 cents per therm (UP about 45.7 percent from August 2024)
Mt. Carmel–39.68 cents per therm (UP about 13.2 percent from August 2024)
Nicor Gas–52.00 cents per therm (UP about 44.4 percent from August 2024)
North Shore Gas–35.94 cents per therm (UP about 14.4 percent from August 2024)
Peoples Gas–43.15 cents per therm (UP about 16.3 percent from August 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 and June.
- 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.
