Why my macarons always crack

It's been years since I first started baking macarons and up until today, I'm still getting cracked batches every now and then. It's really frustrating when you followed all the steps and technicalities and it still fails.

Today, i figured the culprit: Oven temperature. Yes, it has nothing to do the my measuring, meringue consistency or mixing. It is the oven temperature. All the while I was baking at 130C but the perfect temperature to bake in my oven (La germania Italia) is only 110C as per my Tala temperature reading. Yes I dont rely on my oven temperature gauge because it's analog and very inaccurate. I also realised that oven temperature fluctuation of 10-30 degree is normal, but note that macarons are very sensitive so you really have to make sure you achieve a steady state before popping your tray. So word of advise: if you think you did nothing wrong in your mixing, measuring and meringue, check temperature. Make sure you preheat it first and let it reach a stable state with no fluctuations in temp. If possible use a separate temperature gauge for accuracy (I'm using Tala). If you don't have one, just lower than the temp in the recipe you're using to -10 degree. If you're still getting cracks, lower it some more. 

See the temp reading in the below picture. No cracks so far. If you noticed the flat feet, that's due to overmixing.