♥ dwm
♥ google
♥ perl

if your terminal does not support unicode (I just discovered that PM code blocks do not...), consider changing the i subroutine to be something more visible

#!/usr/bin/perl -w
use strict;
use encoding 'utf8';
use Weather::Google;
use Math::Units qw/convert/;

my $LOCATION = "Nowhere"; # set to city name or postal code
my $gw = new Weather::Google($LOCATION);

# single-character icons for weather conditions
# returns one string with one icon per argument
sub i {
    my $i='';
    $i .=    /sun/i ?                        
                chr 0x2600 :
            /cloud/i ?
                chr 0x2601 :
            /rain|shower/i ?
                chr 0x2602 :
            /snow/i    ?            
                 '*':
            $_ foreach @_;
# the above regexes probably don't cover ALL conditions
# but they do cover the ones I have seen over the past few days
    return $i
}

# format a temperature
# originally the second argument was $f but I found that 
# I had to convert the temperature much more than I had to 
# not convert the temperature. If you are one of those types 
# that thinks in non-SI units, you might want to change that.
sub t {
    my ($t, $c) = @_;
    return int($c ? $t : convert($t,'F','C')) . chr 0x00b0;
}

print '[', t($gw->temp_c,1), '(',t($gw->forecast(0,'high')), '/',
        t($gw->forecast(0,'low')), ')',
        i($gw->forecast(0,'condition')), '|',
        i($gw->forecast(1,'condition')),
        t($gw->forecast(1,'high')), '/',
        t($gw->forecast(1,'low')), ']';
[download]

The above script produces something like [17°(18°/5°)☂|☀23°/11°] A newline is omitted because the script's output is combined with other scripts' outputs to create a single string of statuses and notifications. If you want to run it alone on the command line, I suggest adding ;echo to the end of your invocation.

Thanks to Daniel LeWarne for the module!