How reliable is University of Illinois Willard Airport?
Flights from CMI departed within 15 minutes of schedule in 85% of 10,267 flights in official BTS history — and weather is calmest in Jun. Here’s the full picture before you book.
Reliability score
on-time, cancellations & delays
Weather favorability
year-round climate
Origin-airport operations
What the departure punctuality at CMI looks like
On-time departures
across 10,267 flights
Source: BTS Airport Operations · data through 2026-06-25. Role-specific BTS departure history; advisory context, not a guarantee for any flight.
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Weather by month
When the weather works for you at Champaign
A calm-weather score (0–100) for each month from decades of airport observations — how often conditions disrupt flying, not temperature. Higher is calmer.
Calmest month
Calmest flying weather of the year · 92/100 favorability
Roughest month
Most disruptive — low visibility & fog, snow · 76/100 favorability
The read on CMI
What the numbers say about flying through University of Illinois Willard Airport
Across official performance history, flights from Champaign left within 15 minutes of schedule about 85% of the time over 10,267 flights. That's one of the more dependable operational records you'll see. Pair it with a moderate cancellation rate of 2.2%. When a departure does run late, the typical delay is around 11 minutes.
On weather, Champaign is an unusually calm-weather airport year-round. June is the calmest stretch for flying, scoring 92 out of 100 for favorable conditions, while January is the most disruptive at 76, driven mainly by low visibility & fog and snow. The year is relatively steady, so no single month stands out as one to avoid on weather alone.
None of this guarantees your specific flight — it’s the backdrop. To turn it into a booking, score real flights to Champaign, read how we weigh it all in how the PlaneSane Score works, and brush up with how to pick a reliable flight and avoiding weather delays.
Common questions about CMI
- How reliable is University of Illinois Willard Airport (CMI)?
- Flights from Champaign left within 15 minutes of schedule roughly 85% of the time across 10,267 flights of official history — one of the more dependable operational records you'll see. The cancellation rate runs about 2.2%. It's advisory context, not a guarantee for any single flight.
- What is the best month to fly from CMI for good weather?
- June has the calmest flying weather at University of Illinois Willard Airport. January is the most disruptive, mainly from low visibility & fog and snow.
Planning a trip through Champaign?
Score real flights to and from CMI on reliability, weather, and connection safety — not just price.