The software Mary runs on really doesn't have an easy to check a website and make any intelligent decisions on the data found in said website so again we pass the job to the capable Cliff.  Cliff checks weather when Mary asks and returns two items predicted by the National Weather Service:

1. POP - Probability of Precipitation
2. High Temp

Since we are relying upon the weather man to tell us when we should run our sprinklers and that is just slightly better than pure chance we want to make a weighted decision; in other words the stronger the message he give the more water we are going to lay down.  This system is in western Washington and the system is optimized for this area.

First we start with a runtime of zero each day; then we add 3 minutes for each of the following conditions:

• If the temperature is predicted to be over 64º
• If the temperature is predicted to be over 74º
• If the temperature is predicted to be over 84º
• If the POP is under 60%
• If the POP is under 40%
• If the POP is under 20%

 Once additional rule will reset the runtime to zero:

• If the temperature is predicted to be 64º or less

This script is scheduled to run at 23:00 so then we set a timer for 3 hours so the sprinklers start at 02:00.  Each zone runs for the time calculated above.