I took this http://discourse.weather-watch.com/t/45605 one step further.
Add this
<?php
$ralltimeaverage =
$avrainjan+$avrainfeb+$avrainmar+$avrainapr+$avrainmay+$avrainjun+$avrainjul+$avrainaug+$avrainsep+$avrainoct+$avrainnov+$avraindec;
$ravrainalltime = $ralltimeaverage / 1;
$ravrainalltime = number_format((round($ravrainalltime,2)),$places);
$rcurrentmonthaverage =
$avrainjannow+$avrainfebnow+$avrainmarnow+$avrainaprnow+$avrainmaynow+$avrainjunnow+$avrainjulnow+$avrainaugnow+$avrainsepnow+$avrainoctnow+$avrainnovnow+$avraindecnow;
$rmonthraintrend = $rcurrentmonthaverage / 1;
$rmonthraintrend = number_format((round($rmonthraintrend,2)),$places);
if($rannualtrend > 0) {
$trendimage='ajax-images/rising.png';
}
else {
$trendimage='ajax-images/falling.png';
}
?>
just before the table tag for the rain section in ajax-dashboard.php.
And add this
<tr>
<td class="data1" nowrap="nowrap">YTD Diff:</td>
<td style="text-align: right;" class="data1">
<?php echo gen_difference($avg_ytd_rain, $ralltimeaverage, $uomRain,
' %s'.$uomRain.' above avg YTD Rain.',
' %s'.$uomRain.' below avg YTD Rain.') ?>
</td>
</tr>
to have a new row showing the current YTD Diff from Yearly avg.