The Sahm Rule identifies signals related to the start of a recession when the three-month moving average of the national unemployment rate (U3) rises by 0.50 percentage points or more relative to its low during the previous 12 months.
While intended for monthly U3, here is applied to weekly insured unemployment using 6 weeks moving average change by .5% to the preceding 26 week minimum. For California being NSA, it is when the state rate exceeds the previous 26 week minimum by 1.5%.
FRED ‘IURSA’ is used, but being seasonally adjusted the NSA insured unemployment rate for California is used, ‘CAINSUREDUR’.