there are 2 types of windy days - the gusty day ie turbulent, and the steady breeze.

If you have a very steady laminar air flow, then your parkflyer should be ok even if it will squirm a little and resist when turning into the air flow.

It's the gusty day that will cause you serious problems. Simple truth is that a still day is ideal for a small light plane. Blowy weather makes 'em skittish and unpredictable and in the worst case, uncontrollable.

Gusty weather also results in shorter run times as the propeller experiences the aviation equivalent of "wheel-spin" in automobiles. The wing also experiences partial stalls due to the inonsistency of the airflow and this means you have to run your motor that much harder to get the same climb as you would on a still day.

Lightly loaded models are wonderful to fly and are by far the best for the inexperienced pilot, but unfortunately they are also the ones which suffer the most in wind as they get buffeted around horribly. On a calm day they are heaven, in the wind they can be nightmarish.[:@]

Best way to enjoy your plane by waiting for suitable conditions. A great way to practice during inclement weather is with a flight sim. Fantastic for orientation skills and even for practicing aerobatics. Aerofly Pro is considered to be an excellent choice and is peerless from the point of view of flight realism and physics

Hope this helps
I.F.