Predictions are shown in Mountain Time.
Eruptions cannot be predicted with absolute certainty and estimates are derived from user reports.
GeyserPrediction
GrandGeyserTimes 19:41 ± 105 minutes
Old FaithfulGeyserTimes 16:17 ± 13 minutes

Predictions courtesy of:

GeyserTimes GeyserTimes
NPS National Park Service

(*) Prediction derived from double interval