While several gas utilities in Illinois, thankfully, reported lower prices compared with last June, one company, Liberty Utilities, reported a spike of about 33 percent, according to a CUB review of June prices.
Illinois utilities file their supply price, called the Purchased Gas Adjustment (PGA), each month with the Illinois Commerce Commission (ICC). Roughly eight out of 10 Illinois homes use methane gas for heat.
Prices seem to be easing for many customers. Over the past year, a number of factors increased demand and tightened supply to push up prices, including winter storms and increased liquified gas exports (gas producers and marketers are sending the heating fuel outside the United States). New and proposed data centers that are increasing electricity bills also have helped raise gas prices, because the fuel is used for electricity generation.
While the war in Iran has spiked heating gas prices in other countries, the United States’ domestic gas supply has so far been ample enough to protect customers here, experts say. Warmer weather and lower demand also helps ease prices.
Here’s a summary of the gas supply rates charged by Illinois’ major utilities:
- In June, only two utilities were charging higher prices than last month: Ameren Illinois (about 2 percent higher) and Consumers Gas (about 6 percent higher). These companies charged lower prices, compared with May: Liberty Utilities (about 13 percent lower), MidAmerican Energy (about 17 percent lower), Mt. Carmel (about 44 percent lower), North Shore Gas (about 16 percent lower), and Peoples Gas (about 20 percent lower). Nicor Gas and Illinois Gas charged about the same as they did in May.
- Compared with June of 2025, this month’s prices were lower for five utilities, ranging from about 17 percent lower for MidAmerican Energy to about 33 percent lower for Nicor Gas. Consumers Gas did not immediately post its new price.
June 2026 Gas Prices
Ameren Illinois–50.29 cents per therm (UP about 10 percent from June 2025)
Consumers Gas–48.39 cents per therm (DOWN about 14 percent from June 2025)
Illinois Gas–44.13 cents per therm (DOWN about 21 percent from June 2025)
Liberty Utilities–74.90 cents per therm (UP about 33 percent from June 2025)
MidAmerican Energy–40.48 cents per therm (DOWN about 34 percent from June 2025)
Mt. Carmel–25.10 cents per therm (DOWN about 20 percent from June 2025)
Nicor Gas–36.00 cents per therm (DOWN about 33 percent from June 2025)
North Shore Gas–42.37 cents per therm (DOWN about 20 percent from June 2025)
Peoples Gas–36.76 cents per therm (DOWN about 34 percent from June 2025)
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 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.
- Ask if your utility offers a discount program for qualifying customers. Ameren, Nicor, North Shore and Peoples Gas do.
- See if you qualify for energy assistance. To apply or learn more about the Low Income Home Energy Assistance Program (LIHEAP), visit this state of Illinois webpage. (Also, check out our Step by step guide to applying for LIHEAP.)
- Practice energy efficiency. For tips and information about helpful energy efficiency programs, 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’s gas 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
- CUB’s chart of historical gas prices. Plus, CUB’s gas-price reports from 2026: January, February, March, April, May and 2025: January, February, March, April, May, June, July, August, September, October, November, and December.
- If you want to 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, such as electric heat pumps and induction stove tops.
