The German airline said Thursday (August 4) it had made the call due to staff shortages.
Carriers have struggled to cope with the quick rebound in demand.
It comes with customers ready to fly after two years of health crisis restrictions.
Huge queues have built up at airports this year, while many travelers have experienced last-minute cancellations.
In response, Lufthansa will offer only around 80% of pre-health crisis passenger capacity in the coming three months.
Booming demand for air cargo helped Lufthansa return to operating profit in the second quarter though.
Earnings before interest and tax hit just under $400 million for the three months to June.
But the carrier's passenger airline business posted a loss of around $88 million.
It was hit by costs related to flight disruptions.
Rivals Air France-KLM and British Airways-owner IAG also reported a return to profit last week.