Update, May 27, 2022: Tioga Pass Road is open for the season. There may be construction delays.
In general, there are no set dates for any of these events. The roads close when we get snow and they reopen when the plows punch through. Sometimes in a low-snow year, it can still take time to get the roads open. In 2021, for example, we had a drought year, but clearing Glacier Point Road was slowed by the large number of downed trees from the Mono Wind event.
In other words, there is no scheduled opening date and we usually do not know when the road will open until shortly before it does.
Note: In 2022, Glacier Point Road will be closed for the entire season due to road construction.
Is There a Rule of Thumb?
If you’re a bit of a gambler, you can make an educated guess based on the full list of opening and closing dates since 1996. As all the investment houses say, past performance is no guarantee of future results. Next year could be the snowiest year on record or the driest year on record.
Still, you can run some basic calculations. See below the videos to see what the odds are that a given road is opened or closed by a given date.
Why Does It Take So Long?
This video from an April flyover from 2017 (a big snow year) shows the scope of the task.
And this tells you a bit about the plowing process:
Opening Date
If you’re a gambler and you want to play the odds, you can make some guesses based the NPS list of opening and closing dates. That list gives more details, but here are the running tallies for how common it has been for the roads to be opened by a given date.
Glacier Point (1995 to 2020)
- Opened by Mar 31: 4%
- Opened by Apr 30: 19%
- Opened by May 10: 38%
- Opened by May 20: 58%
- Opened by May 31: 88%
- Opened by Jun 11: 92%
- Opened by Jul 01: 100%
The median opening date for the Glacier Point Road is May 16 (1996 to 2015).
Tioga Road (1995 to 2020)
- Opened by May 01: 0%
- Opened by May 15: 27%
- Opened by May 31: 62%
- Opened by Jun 10: 65%
- Opened by Jun 20: 81%
- Opened by Jul 01: 100%
The median opening date for Tioga Road is May 21 (1996 to 2015).
Closing Dates
The short answer on this question is that there is a very good chance both roads will be open in early November and a very good chance both roads will be closed by early December.
If we look at the 21 years from 1995 to 2015, inclusive:
Glacier Point Road (discounting three years with no records)
- Closed on or before November 10 seven times (39% of years)
- Closed on or before November 20 twelve times (67% of years)
- Closed on or before November 30 fifteen times (83% of years)
- Closed on or before December 10 sixteen times (89% of years)
- Closed on or before December 20 eighteen times (100%)
In short, it’s rare for Glacier Point Road to close before November 1, but if you want a better than 50% chance of being able to drive out Glacier Point Road, come in early November.
Tioga Road
- Closed on or before October 31 three times (14% of years)
- Closed on or before November 10 eight times (38% of years)
- Closed on or before November 20 fifteen times (71% of years)
- Closed on or before November 30 eighteen times (86% of years)
- Closed on or before December 10 nineteen times (90% of years)
- Closed on or before December 20 twenty times (95% of years)
- In the 2011 season, the Tioga Road did not actually close until January 17, 2012.
As for Glacier Point, you have a good chance in early November, but in late November not so much.