Database view web page c# data refreshed from timer

Web App is c# , asp.net. DB is sql server

I am writing an app which will give the options to view several queries from a database. This will only READ data from the database There is a concern about taxing the database so I have the following requirement.

" Of particular importance here is that the web app itself functions on a timer to refresh the data related to the tables. When a user refreshes their screen, the refresh should come from the cached data and should not go back to the db. "

Obviously, I can put a timer in there, but assuming there are multiple instances of this web form up there how to I catch the data somewhere so that for example I only have to hit the database once in 30 seconds and 20 instances of this web page can all read this cached data?

Is there a best way to do this?