I believe your answer to be incorrect. As somebody pointed out, daily measurements can vary significantly for various reasons. This is not going to change of you measure weekly, or monthly. The variation is going to be the same. The only way to have an accurate picture is to have daily measurements but paying attention to the trend, not to the daily measures themselves.

Think of it as paying attention to NP or 3-10 second power instead of instant power which can be all over the place.