The couple opened Darwen Aldridge Community Academy and announced a youth award named after the prince.
Adoring crowds lined up early Monday in Blackburn to get a glimpse of the royal couple. One of them, Lillian Sleigh, braved the weather in her wheelchair, which was decorated with Union Jack flags and pictures of the royal couple.
"I came here early, even though it's pouring with rain, to make sure I get the best chance of seeing William and Kate," she said. "They're a lovely couple and as for William, his mother Diana would have been so proud of him."
They also visited a park as part of William's philanthropic efforts to protect outdoor recreational spaces.
The couple will marry at Westminster Abbey on April 29.
The Associated Press contributed to this report.