The local tourism marketing organization for my county is among the groups who encourage locals to celebrate "727" on July 27. This is our area code and the idea is to celebrate the local culture, history, and community. There are local deals and so forth available to those who live within the county.
You can take this idea and pick a week that matches your own area code. Use it to focus on books about local history, culture and food. For some places (Maine, New Hampshire) there is one area code for the state which gives you many options. For others, it may be limited to a city.
Set up a display with signage that echoes the date (Celebrating [area code]). With some planning, it may be possible to involve local businesses. Local bakeries or coffee shops can recommend books or do pairings with different treats or drinks. This can be posted in the library as well as in their establishments. Ask local civic, government, and community leaders for their reading suggestions and use that as a social media post or display.
This is a great theme to take out of your library, unshelving the library to your community. There are always people who need to be reminded about the services and items your library offers. Bringing information about your digital services is a great topic for this sort of unshelving. This will increase your users and those who are invested in your library.
Don't forget to look outside of any special local collection you have to include fiction by authors from the area, biographies of people from the area, and non-fiction related to your area. If you have movies filmed locally or about local issues in your collection, add them as well.