Aside from returning weather statistics such as temperature which are saved in the image header, the most important task for weathd is to determine when the weather gets ``bad.'' Any detection of precipitation is deemed bad. The operator can configure other definitions of bad weather conditions, triggering on windspeed, dewpoint, humidity or temperature. Upon detection of bad weather, weathd immediate sends out a SIG_ROTSE signal to the entire daq system, and issues a weather alarm for rotsed in its status structure. This causes the current exposure to abort, the mount to stop slewing or tracking, and the clamshell to close. weathd will wait for at least one hour to check if the weather has cleared.