While five major gas utilities in Illinois reported lower prices compared with last July, several are charging higher supply rates—including Liberty Utilities and Consumers Gas, which are charging a
whopping $1.03 per therm and $1.83 per therm this month, respectively, according to a CUB review of gas supply 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. 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.
In its filing, Liberty Utilities reported that its supply price, which was already elevated, was up another 37 percent from June, “due to the residual effects of Winter Storm Fern in late January, which led to higher gas prices and a resulting under-recovery of gas costs included in current rates.” The utility used the same explanation for its high prices back in April. Consumers Gas’ filing said that any price variances “are due to the changes in natural gas prices, temperature changes, and balancing the over and under billings each month.” An accountant with Consumers Gas told CUB a number of factors–including volatile winter weather, such as Winter Storm Fern–increase costs and force the company to make up for under-collection in previous months.
Other factors that make heating gas prices volatile include increased liquified gas exports (gas producers and marketers are sending the heating fuel outside the United States) and even soaring energy demand caused by data centers–because gas is used for electricity generation.
Here’s a summary of the gas supply rates charged by Illinois’ major utilities:
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In July, seven utilities charged higher prices than they did in June: Consumers Gas (about 278 percent higher), Mt. Carmel (about 153 percent higher), Liberty Utilities (about 37 percent higher), MidAmerican (about 13 percent higher), Peoples Gas (about 6 percent higher), Ameren (about 0.23 percent higher), and North Shore Gas (about 0.21 percent higher). Illinois Gas charged a supply rate that was about 6 percent lower, and Nicor’s price was the same as it was the previous month.
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Compared with July 2025, five utilities charged lower rates, ranging from about 21 percent lower to 33 percent lower than last year. The four utilities that charged higher prices ranged from about 12 percent higher than last July to about 164 percent higher. See July’s prices below:
Ameren Illinois – 50.40 cents per therm (UP about 12 percent from July 2025)
Consumers Gas – $1.83 per therm (UP about 164 percent from July 2025)
Illinois Gas – 41.71 cents per therm (DOWN about 27 percent from July 2025)
Liberty Utilities – $1.03 per therm (UP about 100 percent from July 2025)
MidAmerican Energy – 45.78 cents per therm (DOWN about 22 percent from July 2025)
Mt. Carmel – 63.41 cents per therm (UP about 61 percent from July 2025)
Nicor Gas – 36.00 cents per therm (DOWN about 33 percent from July 2025)
North Shore Gas – 42.46 cents per therm (DOWN about 0.21 percent–about the same as July 2025)
Peoples Gas – 39.11 cents per therm (DOWN about 21 percent from July 2025)
Note: Your utility is determined by where you live, so you cannot switch from one utility to another. 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 energy assistance and 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 June.
- 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.
