It's been 88 days since the average 30yr fixed mortgage rate was as low as it is today--close enough to 3 months.  Some lenders may be higher or lower than they were yesterday depending on whether or not changed rates yesterday afternoon.

Mortgage lenders prefer to set rates once per day, but can "reprice" if the underlying bond market moves enough in one direction or the other. Bonds improved enough yesterday afternoon for many lenders to offer slightly lower rates.  Those lenders are a hair higher today, generally.  

In terms of the underlying bond market, things are just a bit better right now compared to yesterday morning and just a bit worse compared to yesterday afternoon. That deterioration mainly followed this morning's job openings data which showed another increase from the longer-term lows seen 2 months ago. Rates typically move higher if job openings are higher than expected, all else equal.

But today's data-driven volatility is nothing compared to what could be seen on Thursday morning following the big jobs report (officially, the "Employment Situation" which offers a count of jobs created in June as well as an update to the unemployment rate).