Adding extra information for missing values for Rainfall?

[rdstern]

@lilyclements I keep being asked about methods for infilling climatic missing values. One item is for odd missing rainfall days. One option, in our current dialog, is to choose a reasonable value from that month in another year.

This is because, even one missing rainfall day in the year currently means we omit that year.

I am happy to include a typical value as long as I am reasonably sure that I'm not hitting a possible cyclone, period in that country etc. In general it could be useful for countries, or stations to be able to study those periods. Maybe they should anyway be treated separately? I assume there might be datasets we could add into the R-Instat library to check this aspect, both in their own right, and also to help on this infilling process.

Any ideas?