According to PlainFlights' airport traffic ranking (BTS On-Time Performance total flights), Decatur, IL (DEC) ranks #261 of 382 tracked US airports by total flights (most flights = #1). Decatur, IL posts above-median on-time performance among the 382 tracked U.S. airports, as a smaller regional airport.
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DEC on-time rate vs. the national average
Ahead of the U.S. average across all 382 tracked airports.
Volume vs. on-time rate
Where Decatur, IL sits on volume vs. on-time rate
Among the 382 U.S. airports in the BTS corpus, Decatur, IL handles more flight
volume than 32% of them, and has a higher on-time rate than
62% of them, placing it in the quadrant for quiet and reliable.
Flight volume and on-time rate are independent figures: a busy airport can still run
reliably, and a quiet one can still run late.
Decatur, IL vs. a 29-airport national peer sample, volume percentile vs. on-time-rate percentile.
Total flights (2020-2025): 9,084 ·
On-time rate: 84.5%
Delay Cause Breakdown
Top delay cause: Carrier.
Total delay minutes106,781 min
Carrier52,263 min · 49%
Late Aircraft42,538 min · 40%
NAS (National Aviation System)6,492 min · 6%
Weather5,488 min · 5%
Security0 min · 0%
Source: U.S. DOT Bureau of Transportation Statistics, On-Time Performance
DEC - seasonal on-time pattern
Best: October (94.9%) · worst: December (90.6%)
DEC - on-time rate by year
2020–2025, year-over-year trend.
DEC - taxi-out and taxi-in (monthly)
Average taxi-out 14.9 min · taxi-in 4.8 min over the last 24 reported months (U.S. airport mean taxi-out ≈ 16.4 min).
DEC's average taxi-out (14.9 min) sits near the recent U.S. airport mean (~16.4 min). Month-to-month, it swings from 10.8 min (March 2024) to 18.3 min (June 2025).
Two PlainFlights-derived comparison paths for Decatur, IL, both outside Illinois so the neighborhoods are not same-state geography. Axes stay disjoint: volume peers exclude the on-time peer set. Same-state compare stays below.
The standout signal at Decatur, IL is the delay mix: Carrier owns 48.9% of 106,781 delay minutes across 9,084 BTS flights. The on-time headline is 84.5% (5.5 pts above the 79% national average), with 1,405 delayed and 154 cancelled (1.70%).
Delay minutes concentrate in Carrier (39.8% late-aircraft, 48.9% carrier, 6.1% NAS, 5.1% weather, 0.0% security). As a quieter airport, a single late inbound can swing the month more than at a mega-hub.
On the multi-year calendar, DEC is strongest in October (94.9% on-time) and weakest in December (90.6%), a 4.3-point swing. Volume peaks in April (~141 flights/month). The busiest connecting route is to ORD (Chicago) at 82.6% on-time. Field definitions: on-time performance explained.
Decatur, IL vs. the national on-time distribution
On-time rate among all 382 tracked U.S. airports
84.5%Top 38%higher than 62% of 382 airports
Decatur, IL
60%95%
U.S. airports by on-time rate, bucketed by value
Each bar is a band; taller bars hold more airports. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Data Source: Bureau of Transportation Statistics (BTS), On-Time Performance Data (2020–2025).
Statistics reflect cumulative performance across all available reporting periods. On-time rates exclude cancelled and diverted flights.
DEC's on-time book is mid-pack; month and delay-cause mix move more than the headline rate.
Check the busiest route from DEC before you book a connection. See top routes →
Travel in October rather than December if your dates are flexible. Seasonal patterns →
Gate-to-wheels taxi-out averages 14.9 min here; check the monthly series before a tight connection. Taxi times →
On-time rate reflects the BTS historical average across all reporting carriers at this airport, not any single flight or airline.
Frequently Asked Questions
What is Decatur, IL's on-time rate?
Decatur, IL (DEC) has a 84.5% on-time rate across 9,084 BTS-tracked flights (2020-2025), 5.5 pts above the 79% national flight-weighted average; that places it in roughly the above-median on-time performance.
How does DEC rank among U.S. airports by traffic volume?
Decatur, IL ranks #261 of 382 tracked US airports by total BTS flights (most flights = #1), making it a smaller regional airport.
What's the most common cause of delays at Decatur, IL?
Carrier is the leading delay cause at DEC, accounting for 48.9% of delay minutes. The full breakdown: 39.8% late-aircraft, 48.9% carrier, 6.1% NAS/air-traffic-control, 5.1% weather, and 0.0% security.
When is the best time to fly through Decatur, IL?
October is historically DEC's strongest month at 94.9% on-time, while December is the weakest at 90.6%, a 4.3-point swing across the BTS historical record.