Best time to fly Johnstown to Chicago
Every month pooled across the years on record, so "July" means July generally rather than one particular July. Full JST to ORD record →
Best month
October
91.9% on time · 62 flights
Worst month
February
56.9% on time · 56 flights
| Month | Flights | On time | Cancelled | When late, by |
|---|---|---|---|---|
| January | 62 | 61.4% | 6.45% | 197 min |
| February | 56 | 56.9% | 8.93% | 111 min |
| March | 62 | 64.9% | 8.06% | 144 min |
| April | 60 | 66.7% | 5% | 234 min |
| May | 62 | 80.6% | 0% | 104 min |
| June | 60 | 67.2% | 3.33% | 184 min |
| July | 62 | 79% | 0% | 142 min |
| August | 62 | 78.7% | 0% | 82 min |
| September | 60 | 85% | 0% | 235 min |
| October | 62 | 91.9% | 0% | 92 min |
| November | 58 | 72.7% | 5.17% | 230 min |
| December | 60 | 60% | 8.33% | 282 min |
What a seasonal pattern can and cannot tell you
Months differ for reasons that repeat — summer thunderstorms in the American interior, winter fog and de-icing in northern Europe, school holidays filling every seat and leaving no slack in the schedule. Those are real and they come back each year.
What the pattern cannot do is forecast a particular flight. A quiet month has late days and a bad month has punctual ones. Treat this as a way to choose between two dates you are indifferent about, not as a promise.