[TassyJim]

Thanks again.
I was hoping the value for these capacitors was not too critical. I'm not clear as to how the values are calculated, is there some sort of formula or ??

Cheers!

The capacitors across the rain and wind inputs help eliminate contact bounce.
These capacitors also help reduce RF interference, especially from the long leads going to the sensors.
Other capacitor are across the power supply rails to reduce any noise caused by the high frequency switching, something that all processors do.

While you can calculate ideal values for some situations, the usual practice is to add 0.1uF capacitors in all likely places. If very high frequencies are involved, 0.01uF capacitors are often used.
If your capacitors are 0.047uF as your meter suggests, they are perfectly OK to use and will be just as effective as a 0.1uF
I can't see anywhere in the circuit whey capacitors are used for timing (when the value would be significant)

Jim