Is it true even in October, the Hawaiian sun can still burn?

[OptimusPrime69]

I've been sunburned in southern California in mid-November, so I'm sure in Hawaii in Oct u can still burn. Barring clouds

[winkosmosis]

BTW keep in mind when you calculate based on latitude, the insolation you're calculating is energy per area on the ground mainly, with some impact from thickness of the atmosphere.

But your skin isn't horizontal. Parts of your body will be facing the sun directly no matter what latitude you're at.

[Bay2LA]

The reason Hawaii can still produce UV of 9 in October is due to the fact that sun intensity is a sine function of the angle of incidence. You'll notice in the page below that high sun angles produce very high intensities above 60 degree angle of incidence. Also, there is a huge fall off below 40 degree sun angle. On October 20th with a 58 degree sun angle in Honolulu, the intensity is still 85% intense as the overhead maximum.

6(i). Earth-Sun Relationships and Insolation