This information is set up to answer the often-asked question by many Mt Whitney
 hikers, who have a permit for May, June or July.  The switchbacks are covered
 by snow and unuseable until enough snow melts that the trail can be followed.
        April             Most     Hwy 120    days    April
      Snowpack   First    people   Tioga      after  Crabtree
Year    Level     use     using     Open      Tioga   water
-----  -------  -------  -------  ---------  ------  -------
2023    300%
2022     27%
2021     60%     Apr 15              May 27                 Snow shoveled at the cables 5/5/21
2020                                                        2020 closed due to COVID
2019    150%     June 7   July 7    July 1     6       27"  Lots of snow in May.  Snow shoveled 6/7/19
2018     50%     June 7   June 16    May 21    26      11"
2017    160%     July 9   July 14   June 29    10      44"
2016     85%     June 5   June 15    May 18    27      15"
2015     20%     June 1   June 8     May 4     28       1
2014     25%     June 2   June 13    May 2     28
2013     40%     May 23   June 4     May 11    12       7
2012     50%     May 23   June 4     May 7     16       7
2011    170%     July 9             June 18    21      36
CDEC snow level graphs:
from:  
https://cdec.water.ca.gov/snowapp/swcchart.actionApril Crabtree water:  Water content (inches) for station 253 for April
Link: "Individual Snow Course Historical Data"    
http://cdec.water.ca.gov/cgi-progs/snowQuery...By the way, there are no ads on this site -- it runs on donations.  Small amounts
 are welcome.  The donate link is to the left.