Data aggregation for drawing graphs

Hi,

I want to store data from my weather station and visualize them with graphite. I receive the values once every minute. My storage is big enough, so that I can store the date in this resolution for 20 years.
So if i look at the data from a whole year 2 years ago there is a huge amount of data which would be displayed. Is there an opinion where I can aggregate the data, which would be displayed to, for example 1000 datapoints/graph?
I don't want to loose the data, I got. I just want to let the browser draw the graph with such a big amount of data.

Thank you for your help.