You probably should.
Veteran travelers know that flying out early in the morning is less likely to be affected by planes not showing up from other points, since they generally are on the ground overnight. Vice-verse, taking a Southwest 8pm flight is MUCH more likely to be delayed or canceled since your particular plane could have flown 4-5 short routes that day and could have gotten stuck in any number of cities before it arrives at your particular airport.
Well, here some advice on how to determine which flights are MORE LIKELY to be late or have historically been canceled. I found it in this great blog post titled "Travel Maze: Playing Airline Russian Roulette". If you click on the link it provides, you can access data from the Dept./Bureau of Transportation concerning any specific flight or airport. In the article itself, you will discover a certain flight out of La Guardia to Boston's Logan was canceled over 1/6th of the time. And that Delta cancels flights out of La Guardia almost one percent more often than all other airlines.
This kind of information can make the difference to you choosing an individual airline, certain flight or even an airport stopover point. What's the old axiom - Knowledge is Power?