How to colormap a scatter plot on a map?

I'm new to the mapping toolbox on MatLab and was having a hard time finding how to use color map/mapping.

Essentially, I have the coordinates for many different watersheds in the United States and also have the annual rainfall of each watershed. I want to have a map that simply plots each point of the watershed, however I want there to be a color map that shows/distinguishes where higher rainfall amounts were. How do I assign a value to a certain scatter point?

I put a picture of simply the watersheds mapped out. But I hope to have a color bar gradiant on the side so the points have differnt colors depending on the rainfall.

Here is how I mapped it. I have another vector that holds the information in the same order of the lat/long of the rainfall.

latlim = [25 50]; lonlim = [-125 -67];

ax = usamap(latlim, lonlim);

set(ax, 'Visible', 'off')

sheds = shaperead('usastatehi','UseGeoCoords', true, 'BoundingBox', [lonlim', latlim']);

geoshow(ax, sheds, 'FaceColor', [1 1 1])

plotm(lat, long, 'o', 'MarkerFaceColor',[0 .2 .5], 'MarkerSize', 3, 'SelectionHighlight', 'on')

Answer 1

[Kojiro Saito]

You can control the color by specifying C value in scatterm or geoscatter. If you can share sample rainfall data, I can show a code in detail.