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July Was the Hottest Month in U.S. History. Your August Ameren or ComEd Bill Is Where It Lands.

Ryan Cook•August 22, 2026•Updated Sep 2, 2026

NOAA made it official on August 10: July 2026 was the hottest month ever recorded in the contiguous United States. Not the hottest July — the hottest month, period, in a record that goes back to 1895. The average came in at 76.9°F, about 3.3°F above the 20th-century norm, edging out the Dust Bowl summer of 1936.

That's a climate headline. Here's the household version. On August 19, ComEd's senior vice president of customer operations said plainly that July's heat waves "are now showing up on customers' August bills." Ameren Illinois customers are opening the same envelope this week.

I've been getting texts from customers in Belleville and O'Fallon who thought something was wrong with their meter. Nothing's wrong with the meter. This is what a record July costs at a summer rate.

The part of the record nobody mentions: the nights

Daytime highs get the headlines, but the number that actually drives a bill is the overnight low. NOAA says July's average minimum temperature was 64.2°F, 3.7°F above normal — the warmest nighttime average on record, beating July 2022 by a clear margin.

Why that matters: a central air conditioner in a brick ranch in Springfield is sized to catch up overnight. When it's 78°F at 2 a.m., it never catches up. It just runs. In my experience, a stretch of hot nights adds more kilowatt-hours to a bill than one brutal afternoon does, because the compressor is cycling for eight extra hours nobody's awake to notice.

The math on an Illinois bill

Let's do a rough autopsy on a typical central Illinois home. These are estimates, not your bill.

Ameren Illinois' supply rate reset on June 1 from 8.769¢ per kWh to 11.326¢ — a 29% jump before you used a single extra kilowatt-hour. ComEd's summer price is 10.399¢. Add delivery charges and fees and most Illinois homes are paying somewhere around 20¢ per kWh all-in this summer.
A home that normally uses 900 kWh in July and used 1,200 kWh in a July like this one — which is a plausible jump for a house that never got to rest overnight — picked up roughly $60 in extra charges. A bigger house with two AC units could be well past $100.
That's on top of the June 1 rate reset, which by itself added something like $20–$25 a month to an ordinary bill compared with May.

Stack the two and an August bill that's $80–$120 higher than May isn't a billing error. It's arithmetic. I wrote up the June 1 summer rate reset when it happened, and the longer story of why Ameren bills keep climbing if you want the background.

What changes on October 1 (and what doesn't)

Here's the honest calendar for anyone staring at a bill they can't comfortably pay.

October 1 — the rate resets. Ameren's 11.326¢ summer price runs through September 30, then drops to a non-summer price. The non-summer price that ran through May was 8.769¢ (it was 8.402¢ from October through December before a January adjustment); the new one isn't finalized yet. ComEd's summer price also ends September 30. I covered the October rate drop in detail — short version, a meaningful dip, not a return to 2021.

October 1 — LIHEAP reopens. This is the one that stings. The 2026 LIHEAP year closed on August 15, four days before ComEd told everyone their August bills would hurt. The 2027 program year opens October 1 for priority households — adults 60+, people with disabilities, families with kids five and under, and anyone disconnected or holding a shut-off notice — and November 1 for everyone else who qualifies. There's a real change buried in this year's rules: for Ameren Illinois and ComEd customers, the income limit moves to 300% of the Federal Poverty Guidelines, roughly $3,990 a month for one person. That's a wider door than last year.

Right now — the bridge. Between now and October there's no LIHEAP, but there is a deferred payment arrangement, and under ICC rules the utility has to offer one to most customers who haven't defaulted on a prior arrangement. It's typically 25% down and the rest over 4 to 12 billing cycles, and the utility is allowed to take less up front. ComEd also offers a 21-day extension, budget billing, and a Low-Income Discount for households at or below 300% of the poverty level. Ameren Illinois has Warm Neighbors Cool Friends (up to $500 for households earning roughly 200% to 300% of the poverty level) and a Supplemental Arrearage Reduction Program (up to $2,000 a year in credits against a past-due balance, if you've applied for LIHEAP). And if you think the bill itself is wrong, the Citizens Utility Board will review it for free.

What doesn't change. The delivery side of the bill — the poles-and-wires charges the ICC approved in December for both utilities — stays put. And the capacity costs inside the supply price, the thing that spiked last summer, are already priced in through next May.

Cheap things that actually help in September

None of these fix the rate. All of them trim the usage, and September still has hot weeks in it.

Nudge the thermostat up two degrees and let ceiling fans cover the difference — the compressor is the whole bill, and every degree it doesn't have to chase is real money.
Change the AC filter. A clogged filter makes the system run longer for the same result.
Push laundry, the dishwasher, and the dryer to after dark, when the house isn't fighting the sun and the AC isn't already maxed.
Pull the blinds on the west side of the house in the afternoon.
Ask for budget billing so next August's bill is spread across twelve months instead of landing all at once.

One more thing worth knowing if you're behind: Illinois limits disconnections during extreme heat, and there's a specific gap in the shut-off rules in September that catches people every year.

Where solar actually fits in a summer like this

I'll say the quiet part: a record-heat July is the single best argument for rooftop solar, and also the month people are least able to think about it because they're busy being angry at the bill in their hand.

The argument is simple. The hottest month on record was also a very sunny one. A rooftop system in Champaign or Decatur produced the most it will all year in exactly the weeks the air conditioner pulled the most. With a lease, those kilowatt-hours are billed at a predictable rate set in your contract — as low as $0.10/kWh — instead of the utility's 11.326¢ or 10.399¢ summer supply price with capacity charges riding inside it. Your full rate schedule is set before you sign, so the next record July doesn't get to surprise you.

What solar doesn't do: it won't touch the delivery charges, it won't make the fixed monthly fees go away, and it can't shrink a bill that's already printed. A solar home still gets a bill in August. It's a smaller, more predictable one.

If you want to see what that looks like for your address, run it through our savings calculator — it's an estimate, and I'd rather you see a realistic number than a sales number. The solar lease page explains how the predictable rate works. And if you're an Ameren or ComEd customer who wants the current numbers for your territory, I keep Ameren's rates and ComEd's rates updated.

The bottom line

July 2026 set a 132-year record, and your August bill is the receipt. The rate jumped 29% on June 1 for Ameren customers, the heat added a few hundred kilowatt-hours on top, and the help program that exists for exactly this moment was closed for the season. October 1 brings a rate drop and LIHEAP's reopening; until then, call your utility and set up a payment arrangement before it turns into a shut-off notice.

If you'd rather not do this again next summer, call me at (618) 217-2001 or send a note. I'll give you a realistic estimate for your roof, with all the options on the table.

Frequently Asked Questions

Two things stacked. First, July 2026 was the hottest month ever recorded in the contiguous United States — NOAA puts it at 76.9°F, about 3.3°F above the 20th-century average, with the warmest overnight lows on record too. Air conditioners in Belleville, Springfield, and Joliet ran more hours than in any July in memory, and the August bill is where July's usage shows up. Second, the price per kilowatt-hour was already at its summer peak: Ameren Illinois' supply rate went from 8.769¢ to 11.326¢ on June 1, and ComEd's summer price is 10.399¢. Stack record usage on a summer rate and you get the biggest bill of the year. My rough estimate for a typical central Illinois home: every extra 100 kWh of cooling cost roughly $20 all-in. Three hundred extra kilowatt-hours, which is plausible for a July like this one, is about $60 on top of a normal summer bill.

The rate part should, the usage part already is. Ameren Illinois' summer supply price of 11.326¢ per kWh runs June 1 through September 30. On October 1 it resets to a non-summer price, which historically drops into the 8¢–9¢ range, though Ameren has not finalized the October 2026 number yet. ComEd's 10.399¢ summer price also ends September 30, and its October price gets published in late September. On top of the rate reset, September and October usage falls off sharply as the AC finally shuts off, so two things move in your favor at once. What doesn't change on October 1 is the delivery side of the bill — the poles-and-wires charges the ICC approved in December — or the capacity costs baked into supply. I'd expect a real drop in the October and November bills, but not a return to what you paid in 2021.

Not right now — and the timing is rough. The 2026 LIHEAP year closed August 15, and the 2027 program year opens October 1, 2026. Starting October 1, priority groups can apply: adults 60 and older, people with a disability, families with children five and under, and households that are disconnected or holding a disconnection notice. Everyone else who qualifies can apply starting November 1. One real change this year: for Ameren Illinois and ComEd customers, the income limit moves to 300% of the Federal Poverty Guidelines, which is $3,990 per month for a single person, a wider door than last year's 60%-of-state-median test. Apply through your county's community action agency or at helpillinoisfamilies.com, or call 1-833-711-0374. Until October, the bridge options are a deferred payment arrangement with your utility and the utility-run programs listed in this post.

More than most people use. Both utilities must offer a deferred payment arrangement under Illinois Commerce Commission rules: typically 25% down, and the balance spread across 4 to 12 billing cycles, with the utility allowed to take less up front. ComEd also advertises a 21-day payment extension, budget billing, its Catch Up and Save program with monthly credits toward past-due balances, and a Low-Income Discount for households at or below 300% of the federal poverty level, about $99,000 for a family of four. ComEd says nearly 140,000 customers have tapped more than $60 million in assistance so far in 2026. Ameren Illinois runs Warm Neighbors Cool Friends, up to $500 in bill help for households earning roughly 200% to 300% of the poverty level, just above LIHEAP's old cutoff, plus a Supplemental Arrearage Reduction Program with up to $2,000 a year in credits against a past-due balance for customers who've applied for LIHEAP. Call the number on your bill and ask.

On the supply side, yes — and honestly, that's the side that hurt. The hottest July on record was also a sunny one, which is when a rooftop system produces the most, so a solar home in Decatur or Peoria offset a large share of the kilowatt-hours its air conditioner pulled. With a solar lease, the electricity the panels make is billed at a predictable rate set in the contract, as low as $0.10/kWh, instead of the utility's 11.326¢ or 10.399¢ summer supply price plus the capacity charges inside it. What solar doesn't do is erase the delivery charges or the fixed monthly fees, and it can't retroactively shrink a bill that's already on the kitchen table. My honest framing: solar makes the next record July smaller and more predictable, not free. Run your own address through our savings calculator and see what the estimate looks like for your roof.