Rain day

Now is it going to rain or not.  If it is July 29 and you a betting man, you may be in luck (or out of luck).  There is a story behind this day, Rain Day.  A man had wagered a hat that it would rain on July 29.  He made this bet every year.  As time passed, he amassed a large number of hats as it always rained on this day.  How are you betting this year.  I predict rain and I will raise you a hat.  You in?