d cell areas <tt>A</tt>, we can now get the area-averaged sea surface temperature with <tt>wmean</tt>:</p><pre class="codeinput">wmean(sst,A,<span class="string">'all'</span>,<span class="string">'omitnan'</span>)
</pre><pre class="codeoutput">ans =
         18.45
</pre><p>That's quite a difference from the 13.8 degree value we obtained using the unweighted mean! And it's not surprising: The "unweighted" mean in this context was actually a misnomer because by giving equal weight to each grid cell in the mea