Not a weather-expert but maybe its air moving down from a higher layer in the atmosphere. Check if there's a high pressure zone or a cold-front

I wouldnt worry much about numbers, as long as you enjoy making videos. Remember a certain niche in content on youtube might not reach much further than the audience that is directly interested in it. But I think its only a matter of time before more people will find it. Absolutely love your videos!

yess! I hope the weather won't be too bad heat wise