Don't set it and forget it
The unpredictable weather in May is a good reason why you shouldn't set your sprinkler system and forget it the rest of the summer. This month we have seen a roller coaster of weather from warm temperatures, rain, snow, and back up to warmer temperatures. Hopefully you have been adjusting your irrigation run times as a result of these changes.
If rain is coming, turn off the sprinkler system. If we have an extended dry period, make sure you have those sprinklers set to turn on again. Adjusting your controller throughout the year should be routine and something you check regularly. The result conserves water and money; your checkbook will thank you.