Simple wire-type extensometers (creepmeters), placed across traces of the San Andreas fault system in central California, have produced nearly continuous records of aseismic fault slip (fault creep) for 12 years. The records indicate seasonal and other changes in creep activity that may be responses to variations in local seismicity and rainfall. One frequent type of response is a sudden, episodic movement, or creep event. Onset times of creep events on records from four creepmeters were compared with origin times of local earthquakes and onset times of rain. Seismicity appeared to affect long-term creep rates but did not consistently trigger creep events. Rainfall produced varying responses on the instruments, but when compared annually to total creep, number of local magnitude 2+ earthquakes, number of creep events, and total amount of movement in the form of creep events, total rainfall showed no significant linear correlation with any of the variables. The dry part of the annual rainfall cycle appeared to delay onset of creep events. These 'delayed' events were consistently larger than events during the rainy season.