Illinois Gas Price Predictions & Odds
Illinois gas prices as a market: a daily contract on AAA's statewide average for regular gasoline, from Chicago to Carbondale. The odds sit beside every day AAA has already settled.
The board
Where AAA's Illinois average lands nextPrice history
AAA's Illinois average for regular, as each day settled- Change
- −$0.022
- High
- $4.705
- Low
- $4.665
- Days
- Oct 12 – Oct 18
- Change
- −$0.228
- High
- $4.908
- Low
- $4.645
- Days
- Sep 19 – Oct 18
- Change
- +$0.326
- High
- $4.908
- Low
- $4.276
- Days
- Aug 26 – Oct 18
How Illinois Gas Price Markets Settle
Every Illinois gas contract comes down to one published number: AAA's average price for a gallon of regular gasoline in Illinois on the date the contract names, as AAA posts it on its Illinois page at gasprices.aaa.com. Kalshi lists the daily series as KXAAAGASDIL and writes it under its AAAGAS contract terms, which make AAA the only source agency. Those terms take the figure as AAA has documented it at expiration, set aside any revision AAA posts afterward, and fall back to the last day AAA did publish if a date has no figure.
Each rung is a separate yes-or-no question. Kalshi's Illinois rules resolve a rung Yes only when AAA's average is strictly greater than the rung's price, so a figure that lands exactly on a rung settles it No. The statewide number also blends very different markets. AAA posts its own averages for the Chicago, Rockford, Peoria-Pekin, Springfield and Champaign-Urbana metros, among others, plus county price bands, and none of those local figures is the one the contract reads.
How to Read the Illinois Gas Price Board
The ladder at the top of this page is the coming day's contract. Each rung names a price and shows the chance the market gives that AAA's Illinois average finishes above it, with the venue quoting it named beside the figure. The rungs sit half a cent apart, so the chances fall as the prices climb, from rungs near certainty at the bottom of the ladder to long shots at the top.
The market line is the price where the ladder crosses an even chance, the nearest the board comes to a single expected figure. The last settled day shows where AAA's Illinois average actually landed on the newest date that has resolved, and the distance between the two is the move the market is pricing overnight. Trading on each date's contract stops at 11:59 p.m. Eastern the night before, which is 10:59 p.m. in Chicago.
What Moves Illinois Gas Prices
Illinois taxes gasoline by the gallon and ties the rate to inflation. The Motor Fuel Tax Law (35 ILCS 505/2) raises the rate each July 1 by the rise in the Consumer Price Index over the 12 months ending in March. The Department of Revenue lists the rate on gasoline at $0.483 a gallon from July 1, 2025, through December 31, 2026, because Public Act 104-0468, signed June 16, 2026, suspended the July 1, 2026 adjustment for six months. The department also collects an environmental impact fee of $0.008 a gallon and an underground storage tank tax of $0.003 a gallon. Its rate page lists no gasoline rate for January 1, 2027 or later; this page is next reviewed on November 16, 2026.
Supply ties Illinois to the middle of the country. The Energy Information Administration places the state in PADD 2, the Midwest district it shares with 14 other states from Ohio to Oklahoma. EIA names crude oil as the largest part of the retail price, the input that moves every state at once, and notes that most gasoline travels by pipeline to terminals near where it is sold.
Blend rules split the state. EPA requires reformulated gasoline in Cook, DuPage, Kane, Lake, McHenry and Will counties, with parts of Grundy and Kendall, as the Illinois side of the Chicago-Gary-Lake County area, and in Jersey, Madison, Monroe and St. Clair counties in the Illinois part of the St. Louis area. Everywhere else the federal summer volatility limit applies at retail from June 1 to September 15, and Illinois is one of eight states EPA lists as having opted out of the 1.0 psi ethanol waiver. EIA notes that gasoline demand usually rises in summer.
Illinois Gas Price History
The chart under the board plots AAA's settled Illinois average for each day whose contract has resolved. It starts with the contract for August 26, 2026, the first date in Kalshi's daily Illinois series, and the full view keeps every settled day since. The seven-day and thirty-day windows roll forward one day at a time and always end on the newest settled figure. What the Illinois Gaming Board has said about the exchanges that list these contracts is on the legal status page.
Questions readers ask
What will gas prices be in Illinois tomorrow?
Kalshi's daily Illinois contract prices exactly that question: each rung shows the market's chance that AAA's statewide average for regular finishes the next day above a stated price, and the market line marks where that chance is even. The series has listed a contract for every day since August 26, 2026, and trading on each one closes at 10:59 p.m. Central the night before its date.
Where does the Illinois average gas price come from?
From AAA, which posts a daily Illinois average for regular, mid-grade, premium and diesel at gasprices.aaa.com, next to metro averages such as Chicago Metro and Springfield. Kalshi's Illinois contracts read only the regular-gasoline average, as AAA has documented it on the date each contract names.
When do Illinois gas price contracts settle?
Under Kalshi's AAAGAS terms, trading ends at 11:59 p.m. Eastern the night before the named date, AAA's figure is read at the listed expiration time of 10:15 a.m., 11 a.m. or 3 p.m. Eastern, and the contract settles no later than the day after expiration.
What is the gas tax in Illinois?
The Illinois Department of Revenue lists the motor fuel tax on gasoline at $0.483 a gallon from July 1, 2025, through December 31, 2026, after Public Act 104-0468 suspended the July 1, 2026 inflation adjustment. An environmental impact fee of $0.008 a gallon and an underground storage tank tax of $0.003 a gallon are collected as well.
Are prediction markets legal in Illinois?
Illinois Predictions keeps that question on its legal status page, which sets out the Illinois Gaming Board's letters to prediction-market exchanges, each item dated. Nothing on this page is legal advice.
Will gas prices go down in Illinois?
For the next day, read the market line against the last settled AAA figure on the board: a line below it means the market is pricing a lower Illinois average, and a line above it a higher one. On the tax side, the suspension of the inflation adjustment runs through December 31, 2026.