Predictions are shown in Mountain Time.
Eruptions cannot be predicted with absolute certainty and estimates are derived from user reports.
GeyserPrediction
CastleNPS May 1 @ 08:45 ± 45 minutes
CastleGeyserTimes May 1 @ 10:01 ± 1 hour
GrandGeyserTimes May 1 @ 02:15 ± 105 minutes
RiversideGeyserTimes May 1 @ 00:51 ± 25 minutes
DaisyGeyserTimes 22:42 ± 15 minutes
Old FaithfulGeyserTimes 23:00 ± 13 minutes

Predictions courtesy of:

GeyserTimes GeyserTimes
NPS National Park Service

(*) Prediction derived from double interval