Looping through worksheets, columns and rows

[DaveKimble]

I have rainfall data going back 17 years,
with one year per worksheet, labelled with "year",
one month per column, labelled with "Month"
one day per row, labelled with day-number (empty if invalid day).

I want to do some analysis looking at consecutive runs of days,
so the current layout is not helpful.
I think I want to convert the data to (17*12*31) x 2: year-month-day, rainfall

I don't need the complete working solution, just a hint on the best way to go.
(preferably not with VB)