Querying current weather conditions to make it rain or snow on your site.

step2.php

<div id="bgimgweather">
    <?php
        $url = 'http://w1.weather.gov/xml/current_obs/KSYR.xml';
        $xml = simplexml_load_file($url);
        $currentweather = $xml->weather;
        //$currentweather = "Light Rain";
    ?>
</div>

step3.php

switch (true) {
    case stristr( $currentweather, "Thunderstorm" ):
        echo '<div class="bgimgrain"></div>';
        echo '<div class="bgimgstorm"></div>';
        break;
    case stristr( $currentweather, "Snow" ):
        echo '<div class="bgimgsnow"></div>';
        break;
    case stristr( $currentweather, "Rain" ):
    case stristr( $currentweather, "Drizzle" ):
    case stristr( $currentweather, "Hail" ):
    case stristr( $currentweather, "Showers" ):
        echo '<div class="bgimgrain"></div>';
        break;
    case stristr( $currentweather, "Fog" ):
    case stristr( $currentweather, "Haze" ):
    case stristr( $currentweather, "Smoke" ):
        echo '<div class="bgimgfog"></div>';
        break;
    default:
        //Do Nothing
    break;
 }

step5.css

.bgimgstorm {position: absolute; top: 0; background: url('img/weather/storm.gif') repeat left top; width: 100%; height: 100%; opacity: 0.2;}
.bgimgsnow {background: url('img/weather/snow.gif') repeat left top; width: 100%; height: 100%;}
.bgimgrain {background: url('img/weather/rain.gif') repeat left top; width: 100%; height: 100%;}
.bgimgfog {background: url('img/weather/fog.png') repeat-x left top; width: 100%; height: 100%;}

step6.php

<?php
    $url = 'http://w1.weather.gov/xml/current_obs/KSYR.xml'; 
    $xml = simplexml_load_file($url);

    $currentweather = $xml->weather;
    //$currentweather = "Light Rain";
    switch (true) {
        case stristr( $currentweather, "Light" ):
        case stristr( $currentweather, "Drizzle" ):
            echo '.bgimgfog {opacity: 0.3;} ';
            echo '.bgimgrain {opacity: 0.04;} ';
            echo '.bgimgsnow {opacity: 0.04;} ';
            echo '/*' . $currentweather . '*/';
            break;
        case stristr( $currentweather, "Heavy" ):
        case stristr( $currentweather, "Thunderstorm" ):
            echo '.bgimgfog {opacity: 0.9;} ';
            echo '.bgimgrain {opacity: 0.1;} ';
            echo '.bgimgsnow {opacity: 0.2;} ';
            echo '/*' . $currentweather . '*/';
            break;
        default:
            echo '.bgimgfog {opacity: 0.5;} ';
            echo '.bgimgrain {opacity: 0.07;} ';
            echo '.bgimgsnow {opacity: 0.08;} ';
            echo '/* ' . $currentweather . ' */';
            break;
        }
?>