I have towels/plywood/towels over the window.
I then have 2 places I record.
With that I still need to edit a good deal out, and of course do noice reduction in Audacity.
I have to admit I am somewhat envious of the instructors who have a very quiet environment, and that is definitely on the must-have list for when we buy a house here.
I have a fairly quiet place to film, but to get rid of wind, traffic, and computer fan noise, I've found that a shotgun mic mostly does the trick. Any background noise that's left, I can pretty easily eliminate with Audacity using the Noise Removal plugin and maybe a noise gate if the noise is too embedded in the audio.
I was using iMovie for editing and now using Camtasia for the same. Although I don't have an outdoor shooting, the mic captures the noice of the ceiling fan which sounds just like the background noice on your video.
Both iMovie and Camtasia have a provision to reduce this ambience noice. I use them and it just works for me.