The most likely reason I can think of is the controller is not getting weather data correctly (the weather data you see in the app are data directly from WUnderground website, and do not necessarily represent what the controller receives). Are you setting OpenSprinkler to use static IP? If so, please make sure you also set the correct router (i.e. gateway) IP, otherwise the controller cannot receive data from weather website. We strongly recommend keep OpenSprinkler in DHCP mode, and use the router’s DHCP reservation feature to set a fixed IP to OpenSprinkler.