[bryanrasmussen]

Is it really less intense? When I go out on a sunny day in Denmark it is murder. When I go out on a sunny day in Italy it's generally just overall warm.

At any rate another factor is that in the Northern regions it's my experience people do their best to soak up as much sun as possible.

[da_chicken]

I could believe that if you were near the coast.

I grew up in central Michigan and thought the same about the sun until I spent a few years in southern Arizona. The sun there feels like a heat lamp in summer. The low humidity makes the atmosphere absorb less energy. Although it feels like it's about 5 C cooler than it actually is because sweat evaporates so quickly, but once it gets to 43 C you actually just feel vaguely ill just going outside. Standing in the sun is just not something you do. It's a very unique experience to lick your lips and have your tongue feel cold.

Of course, neither of those were as bad as Houston in August. It was 38 C and 98 % relative humidity. And, I will point out, it had not rained. That's just what it's like. You walk outside and your glasses instantly fog up and you feel like you desperately need to shower.

[chasd00]

I live in Dallas and remember going hiking in Arizona and then getting in the car and the windows fogged up from sweat evaporating. Someone from a humid summer climate being outdoors in a dry summer climate has to really watch their water intake. It doesn't feel as hot because it's sucking all the moisture out of you and by the time you realize what's happening you're already not feeling so great. If you're 5 miles from water you're in a bad spot.

[HPsquared]

The sun is at a lower angle from the horizon at higher latitudes. It passes through more atmosphere, losing some UV, and also the surface irradiance on the ground (energy per unit land area) is lower.

[flossly]

This. What I've learned for VitD conversion in the skin the sun needs to be more than 45° "high". Below that it's not much effective.

Those long summer evenings in northern Europe are thus not all that useful for VitD.

[wtetzner]

I think it's because further north the Sun is at a lower angle in the sky. So high frequency waves like UV (needed for Vitamin D production) get filtered out by passing through more of the atmosphere.

Lower wavelengths like IR (heat) can more easily pass through the atmosphere. And since the Sun is lower in the sky, it hits more of your body. So you might feel more of the heat, while still getting less UV.

[jodleif]

Its about the angle yes, but the main thing is basically for every square unit of solar radiation gets projected onto a larger surface because of the angle- meaning radiation per unit area is lower. The secondary effect is that sunlight has to travel through more atmosphere, and gets scattered somewhat.

[bluedino]

Sit in the sun for a bit closer to the equator. You'll feel it very quickly