Heading outside tomorrow for Independence Day (I cannot imagine I have any non-US readers yet)? Be sure to check out this map on sun exposure, before you step outside…

Found at EPA Sunwise: http://www.cpc.ncep.noaa.gov/products/stratosphere/uv_index/gif_files/uvi_usa_f1_wmo.gif
Quick! Which areas are going to have the highest UV levels? No, it’s not the Upper Midwest and Canadian border, despite those areas being fire engine red and practically flashing “DANGER! DANGER!” It’s the light blue areas in places like Wyoming and Mexico. You know, the ones that don’t stand out at all. The ones that look like cool, inviting water.
It looks like they started out with a rainbow scheme, then somehow ran out of colors at level 9, and had to figure out something else to push it out to 15.
And that’s not to mention the unevenness of the color scheme from 0-9. Look at how much the color shifts from 0 to 2 (dark blue to dark green). Now look at how little it shifts from 6 to 8 (medium orange to red orange). The visual shift for each step changes in magnitude.
One Nice Thing: The color scheme from 10 to 15, on the other hand, has some relatively even, yet easy to distinguish, steps.
Thanks, EPA, for helping keep people in the Southwest calm while the ozone layer disintegrates above them.
You’re wrong about not having any non-US readers :-) Your site was mentioned several times on Twitter where people from all over the world who watch the #cartography tag picked it up. Including me (from the Netherlands).
You have to manually make that color ramp. Chalk this up to “misleading/lying with maps”
Don’t forget that the “worst” level is almost the same color as the 4 “best” levels.
I’m from outside the US and your site rocks!
The thing I notice that probably prompted this color scheme is it’s very close to the Doppler radar returns color scheme, with the exception of the 0-blue, although the radars past 11 tend to go for white rather than faint blue.
If I may play devil’s advocate and defend this trash-tier map, it’s actually going by the inane decision that the UV Index was created with to have red be high and yet have light blue be extreme.