Predictions are shown in Mountain Time.
Eruptions cannot be predicted with absolute certainty and estimates are derived from user reports.
GeyserPrediction
GrandGeyserTimes 14:55 ± 1 hour
RiversideGeyserTimes 14:02 ± 25 minutes
GrandNPS 15:15 ± 75 minutes
RiversideNPS 14:00 ± 45 minutes
DaisyGeyserTimes 14:14 ± 15 minutes
Old FaithfulNPS 14:23 ± 10 minutes
Old FaithfulGeyserTimes 14:21 ± 13 minutes
CastleGeyserTimes May 9 @ 05:31 ± 1 hour
CastleNPS May 9 @ 05:15 ± 1 hour

Predictions courtesy of:

GeyserTimes GeyserTimes
NPS National Park Service

(*) Prediction derived from double interval