Fall 'Freeze' Probabilities (Jul. 31 - Dec. 31)


HEADWORKS PORTLAND W, (353770)
Temp F Earliest 10% 20% 30% 40% 50% 60% 70% 80% 90% Latest
36.5 08/06 09/23 10/03 10/09 10/14 10/19 10/23 10/28 10/31 11/08 11/29
32.5 08/06 10/13 10/25 11/01 11/04 11/10 11/15 11/21 11/27 12/06 12/28
28.5 10/06 11/02 11/13 11/20 11/24 12/04 12/10 12/16 12/24 **/** **/**
24.5 10/30 11/17 12/07 12/15 12/22 **/** **/** **/** **/** **/** **/**
20.5 11/01 12/09 12/19 **/** **/** **/** **/** **/** **/** **/** **/**
Graphic Output
 Earliest - Earliest date when a minimum temperature below the threshold occurred.
            **/** means there has never been a year when the minimum temperature
                  went below the threshold temperature during the July 31 to 
                  Dec. 31 period or insufficient data to determine a date.
            07/31 means the minimum temperature can go below the threshold 
                  temperature any day during the July 31 to Dec. 31 period.
xx% - Percent probability that a minimum temperature below the threshold will occur on or before the given date. **/** means non-occurrence of the threshold or insufficient data to determine a threshold.
Latest - Latest date when a minimum temperature below the threshold occurred. **/** means there has been a year when the minimum temperature didn't go below the threshold temperature during the July 31 to Dec. 31 period or insufficient data to determine a date.

Western Regional Climate Center, wrcc@dri.edu