Attempting to simply JSON extraction ala http://objectpath.org/ in Perl6.

weather.pl

use v6;
use Net::HTTP::GET;
use JSON::Fast;

my $appid = %*ENV{'APPID'} or die "Need APPID in env var from openweathermap.org";

my $contents;

if (1) {
    my $response = Net::HTTP::GET("http://api.openweathermap.org/data/2.5/box/city?bbox=12,32,15,37,10&cluster=yes&appid=" ~ $appid);
    $contents = $response.content;
} else {
   $contents = slurp "weather.txt"; # cached. 
}

say (from-json($contents){'list'}
    .grep: { $_{'main'}{'temp'} > 20 && $_{'clouds'}{'all'} == 0 }
    ).map: {$_{'name'} };