The frequency at which you'll receive a trademark monitoring report depends on your service provider. The market standard is once a month, and for most countries, this is sufficient. However, in the US specifically, this can cause problems.
Let's say your monitoring solution tracks trademark registers and notifies you of similar trademark applications. If you think any of them are confusingly similar to your trademark, you can use your ownership right to oppose the new mark, which you can only do during the mark's opposition window. The opposition window in the US is rather short - only one month. If you receive monitoring reports once a month, you can learn about the mark too late for you to sufficiently look into it and respond.
This is why we offer weekly trademark monitoring reports, so you can rest assured you'll always have plenty of time to weigh in your options and react.