The rate comes from a household survey, separate from the payroll survey that produces the nfp headline, so the two can disagree. A rising unemployment rate is one of the most reliable recession signals (the Sahm rule triggers on a 0.5-point rise from its low).
The fomc has a dual mandate: stable prices and maximum employment. This number is half of that mandate.
Example: unemployment ticks from 3.7% to 4.1% over four months. The three-month average is now 0.5 points above its 12-month low, which historically has coincided with the start of recessions.
Related: nfp, fomc, gdp, economic-calendar