[R] Suggestions for scatter plot of many data

[Rich Shepard]

   I have daily precipitation data for 58 locations from 2005-01-01 through
2018-06-18. Among other plots and analyses I want to apply lattice's
xyplot() to illustrate the abundance and patterns of the data.

   I've used a vector of colors (and a key) when there were only eight
weather stations and the date range was three months. This was very
effective in communicating the amounts and patterns.

   I'm asking for ideas on how to best present these data in a scatter plot.

Regards,

Rich