Illinois’ fall voting season comes to an end with Election Day on Tuesday, the final day for voters to cast a ballot after weeks of early in-person and mail voting in races from U.S. senator and governor down to county officers and judgeships.

Weatherwise, Election Day will be a “meteorological standout,” said retired WGN meteorologist Tom Skilling, with unseasonably warm temperatures and a forecast high of 74 degrees. It could be the warmest Nov. 3 in nearly four decades and more akin to late September, the product of a storm system pushing southwest winds that could gust above 30 mph, he said.

Scattered rain is possible in the late morning and early afternoon, with the chances increasing as the day proceeds, he said.

“Bottom line, weather’s not going to be an issue,” Skilling said. “The unusual late season warmth would seem to support folks who might be impacted by inclement weather instead getting out and voting.”

Polls across the state will open at 6 a.m. and close at 7 p.m. Any voter who is standing in line will be allowed to enter their polling place and cast their ballot.

Even though the polls close on Tuesday evening, local election authorities can count mailed-in ballots postmarked by 7 p.m. Tuesday that arrive within the following 14 days. The law allowing the late counts in states was upheld by the U.S. Supreme Court in June despite opposition from Republicans and President Donald Trump.

On the ballot are races for U.S. Senate, governor and other statewide offices. In addition, so are all 118 seats in the Illinois House, 39 seats in the 59-member state Senate and all 17 of Illinois’ seats in the U.S. House. Locally, races for county clerk, sheriff and treasurer throughout Illinois, as well as Cook County assessor, are on the ballot, along with judicial candidates and judges seeking retention.

In Chicago, the election marks the first time that voters will elect all 21 members of the Chicago Board of Education, including its president.

On Monday, Gov. JB Pritzker, who is seeking to become the first Democrat elected governor of Illinois three times, joined Lt. Gov. Juliana Stratton, the Democratic nominee for U.S. Senate, and local Democrats on a final-day barnstorming tour outside the Chicago area, visiting Collinsville, Springfield, Bloomington, Rock Island and Rockford.

Republican governor candidate Darren Bailey, a downstate farmer and former lawmaker seeking to avenge his loss to Pritzker four years ago, campaigned in Chicago where he made one last appeal for votes at a news conference.

Don Tracy, the former state Republican chair who is seeking the U.S. Senate seat, spent election eve in the suburbs. He stopped at the Wheaton Metra station, and he knocked on doors and walked the Riverwalk in Naperville before heading to a meet-and-greet in Joliet.

Going into the final day before Election Day, more than 1.6 million Illinois voters had already cast early ballots across the state. Nearly 900,000 had voted early in person, and nearly 700,000 mail ballots had been returned, according to Illinois State Board of Elections figures.

After the final campaign weekend, the Chicago Board of Election Commissioners said nearly 300,000 early votes had been cast as of Monday — more than 180,000 in person and more than 100,000 by mail.

On the eve of Election Day, early voting in the city looked likely to outpace the 297,759 early ballots cast four years ago. In that election, nearly 180,000 people voted early in person and more than 118,000 cast ballots through the mail.

Cook County Clerk Monica Gordon, whose office administers elections in the Cook County suburbs, said Monday there has been “tremendous voter engagement in early voting and vote by mail,” with totals exceeding those from four years ago.

As of midday Monday, more than 250,000 suburban Cook County residents had voted early, a 31% increase over the same point in the 2022 election. Mail voting also was strong, with nearly 107,000 mail ballots returned to the clerk’s office, and about 11,000 ballots more were in the U.S. Postal Service pipeline. Gordon said she expects mail voting to exceed the 122,600 ballots cast by mail in 2022.

The final day of voting comes amid efforts by the Trump administration to seek federal involvement in ballot counting in other states as part of the president’s continued efforts to inject uncertainty in the minds of voters over the legitimacy of the voting process.

Comments from members of the administration also raised the possibility of federal intervention in the election, including possible immigration enforcement activity in or around polling places despite legal prohibitions.

The Justice Department has already said it was sending out about 1,000 election monitors to all 50 states. It is the largest-ever mobilization of the agency’s lawyers to watch polling places for possible civil rights violations, such as intimidation and racial discrimination. The department did not respond to questions about how many monitors are being assigned to Illinois.

Officials said the monitors have been instructed not to interfere with voting. Still, there are fears that the monitors may use their roles to collect and present evidence for dubious post-election challenges to the legitimacy of the results.

The Illinois attorney general’s office took note of the Justice Department’s plans in a statement late last week, noting federal poll monitors are not new and have traditionally been deployed to ensure compliance with federal voting laws. The office said it has been in contact with the department and has no reason to believe the federal monitors will be engaged in anything beyond their traditional role.

Still, teams of assistant attorneys general and investigators from the attorney general’s office will be watching the polls and the monitors. They will be joined by hundreds of poll monitors from a coalition of voting rights groups, including the League of Women Voters of Illinois, Common Cause Illinois and the Illinois Coalition for Immigrant and Refugee Rights.

The coalition said it has conducted training and that many of its poll watchers have been accredited by their local election authorities in identifying and reporting suspected cases of voter intimidation, electioneering or election interference.

Gordon said Cook County election officials “have no information that federal officers will be visiting any of our polling places.” She said election judges are prepared to respond “if any situation arises.”

“We want every voter to know that their right to vote is protected, and our job is to make sure they have the opportunity to exercise that right,” she said.

Chicago Tribune’s Dan Petrella, Olivia Olander and Jeremy Gorner contributed.