My experience is within Europe, but I'm pretty sure that the US mandates the implementation of DFS on a range of 5 GHz channels, too. If compliant APs (including Meraki MR) hear radar - or something 'in the air' that looks like radar, while running on one of those channels - they have to immediately change channels and will add a DFS event to the event log. I'd be very surprised if you are being impacted by airport radar, without this manifesting as many DFS events and the majority of your APs ending up on non-DFS channels.
Your experience if configuring your APs to non-DFS only is likely to depend heavily on how busy your RF environment is, generally.