Chicago Marathon Faces Less-Than-Ideal Conditions — image accompanying Marathon Handbook's report. Image accompanying Marathon Handbook’s report; reduced and presented for news commentary with the attributed report. View the complete source report.
Marathon Handbook reports that over 55,000 runners will face warm conditions. The race alert system is set to yellow, indicating less-than-ideal conditions.
The National Weather Service predicts a high of 79 F on Saturday, cooling to 62 F overnight. Sunday's race will see a high near 72 F, with temperatures rising throughout the day. Read more culture coverage.
The alert system, introduced in 2008, warns runners to slow down. Yellow alerts advise caution, while red alerts suggest considering withdrawal due to dangerous conditions. Related: Paris Marathon introduces lottery system for 2027 race.
This original Runner World brief is based on reporting from Marathon Handbook. Visit the source for its complete reporting, context and any later corrections.
Reader questions
Questions about this report
What should runners know about Chicago Marathon Faces Less-Than-Ideal Conditions?
Race organizers warn runners of warm temperatures ahead of Sunday's event. Marathon Handbook reports that over 55,000 runners will face warm conditions. The race alert system is set to yellow, indicating less-than-ideal conditions.
When did Runner World publish this culture brief?
Runner World published this brief on October 7, 2026. The underlying Marathon Handbook report was dated October 7, 2026.
Where can readers find the complete original report?
This summary is based on reporting from Marathon Handbook. The attributed source link in the article leads to the publisher’s complete report.
THE WEEKLY BRIEFING
Start the week a step ahead.
A concise edit of the running stories worth knowing, sent every Monday.
