Example:
%create some data for demonstration
lat = sort(rand(49,1))*180-90;
long = sort(rand(65,1))*360-180;
alt = sort(rand(20,1))*20000;
[latG, longG, altG] = meshgrid(lat, long, alt);
temperature = sort(rand(65,49,20) * 100-50, 3, 'descend');
%now the graphic
pointsize = 20;
scatter3(latG(:), longG(:), altG(:), pointsize, temperature(:))
colorbar
The pointsize is what you missed.
Note that in this, the temperature will not be shown directly, and will instead be encoded as color information.
Alternate graphic:
volshow(temperature, 'colormap', jet);
