The 2020 SoBo's Guide to Baxter and Katahdin.

You’re not going to climb on May 15th, the traditional date for the park to open to overnight camping. The Park closes to all hiking in April, and trails will not open until late May.
Plan your start for later, after Memorial Day at least, June 1st better, second week of June best. I recommend the second week of June to ensure a Katahdin trail will be open. Don’t plan on an up-and-over from the Roaring Brook side. The logistics, the load, uncertain trail conditions – just don’t over complicate your start. The Dudley Trail is closed indefinitely. Come back another day to do the Knife Edge.
In 2019, for the first time in decades, a trail up Katahdin didn't open before June 1st. The BSP Trail Specialist didn't open the Hunt Trail until June 14th. An aberration? Sure hope so.
Read the guide, ask questions, plan ahead.