use strict;
use warnings;

my %some_hash = (
           sunny => .63,
           cloudy => .17,
           rainy => .2
           );

my @key_list = keys %some_hash;
my $max_key = pop @key_list;

foreach (@key_list) {
    $max_key = $_ if $some_hash{$_} > $some_hash{$max_key};
}

print $max_key." :: ".$some_hash{$max_key}."\n";