How Hot Are Vulcan, Tatooine, and Dune?

As you can see from my location, I live in Arizona, which for those of you in other countries who aren't familiar with it, is a very hot desert, in the summers we can get up into the 120s Farenheit. Lately I've been wonder how living here would compare to living on the big SF desert planets like Vulcan, Tatooine, or Arrakis. I know none of the shows or movies have really gone into detail about how hot they get, so I wondering if any of the books or anything like that have ever given any idea of exactly how hot those planets get?

 

Lynch's film version gave the temperature on Arrakis as around 38 iirc (once converted from Kelvin).

I suspect the temperatures on all 3 planets would be mid 30s to low 40s. anything above that and life gets very very hard for humans though we can survived into the very high 40s - some places in Australia have had temps just shy of 50 degrees C recorded a couple of years back (no doubt there are something in Africa for example).

though for all the temperatures, where's the sun protection on Vulcan or Tatooine? Luke's light clothing might help with the temperature but it's a wonder he's tanned darker than palpatine's heart.

 

Cooler than California in July.

 

So it would be pretty close to our summers than. For anyone who doesn't feel like doing the calculations, 120F is 48.9C.

 

Except for places like death valley and other real deserts in California. When the cities get to 120°F, it's really nasty. Going outside is like walking into an oven, and most air conditioning systems struggle to keep indoor temperatures between 78°F - 80°F which honestly isn't all that comfortable for a long period of time - and it's also when we usually start having rolling blackouts or sections of the power grid fail.

Usually we'll get maybe one full 7-day stretch of temperatures above 120°F, In late July or August, and then get a break to where they're down to around 100°F with only the occasional 120°F day. (And thank God at least in Southern California it's a dry heat because I wouldn't want to think about what 120°F with any high level of humidity feels like.)

But yeah over the summer when we get those week long heat waves, It can get really nasty when the temperature gets that high. I wouldn't want to live in an area where that's the average temperature during a heat wave.

 

Yeah, that's pretty much what we're like here. If we hit the 120s at all, it's usually just for a few days over the whole summer, but when we do it's nasty.
You do everything you can early, and once you start getting towards the hottest part of the day, you pretty much just hide inside until the sun sets.
It's never good when you're soaked in sweat within a few seconds of stepping outside your house or car.

 

Probably the closest to an accurate sense of it one can get is: they're all exactly as hot as a piece of string is long. That is to say as hot or as cold as a given story needs them to be.

 

Checked Memory-Alpha and Wookieepedia, neither of which gives any temperature for the respective planets so you're probably on the money there

 

Yeah, we haven't gotten into that level of detail for the established worlds of those universes yet. Not as a matter of routine.

 

Yeah, that's probably true. But I know some of the reference books can get into some pretty tiny details, so I thought maybe there was a chance that they got into the temperatures.

 

That kind of specific granular detail is usually beyond the scope of most storytelling; generally all you need to know is if it's uncomfortably hot, dangerously hot, or "melts lead" hot.
I mean for one thing, we're talking about entire planets, not specific locations on said planets. Even average surface temperature doesn't tell you much from a ground level perspective; for example, last I checked Earth's average surface temp it at about 14°C (and rising!). But right here in the south of England it's now about 11°C (an hour past sundown), whereas in Phoenix AZ it's about 33°C (in the mid afternoon). See how that 14°C figure suddenly seems irrelevant?

It's bound to be a LOT hotter out on the open dunes or salt flats down near the equator, compared to say up in the polar canyons where it might be almost comfortably cool. Also as someone that lives in a desert climate I'm sure I don't have to tell you how cold such an environment gets at night! Indeed since I live in a fairly humid country, I'd be willing to bet the summer nights here are way warmer than they are there (the last couple Julys have been unbearable!) So variance is also a thing.

 

Of course, I just know there are a lot of reference books that have come along that get pretty detailed at times.

 

I guess what I'm getting at is that in order for it to actually mean anything, one would have to model and *entire planet's* eco-system, geology, geography and climatology. The closest any of those came to that is Dune, be even Herbert wasn't *that* hung up on the details.

Still the major factor here isn't really heat, it's humidity. With dry air a human can survive temperatures up to about 70°C over the long term (though they'd still need regular access cooler environs and of course, water.) A more tropical level of humidity and that temperature of survivability drops by about 20 degrees. At high saturation levels, 35 °C is about the limit of liveability and 48 °C or above for any considerable length of time is death. To put that difference in perspective; with dry air a person (speaking in wide generalities of course) wouldn't necessarily die until it got up to something close to 120°C! (Twenty degrees above the boiling point of water, for the metrically disinclined.) So (somewhat counterintuitively) the dryer the air, the more survivable the heat, right?

Now Vulcan, Tatooine, and Arakkis are all depicted as very hot environments, but how arid are they?
Well Vulcan has clouds, open bodies of water, jungle biomes, and it seems a fair portion of the deserts aren't natural but the result of millennia of warfare, nuclear or otherwise (plus whatever industrial period preceded it.) So while it may be the cooler of the three, it may also be the more hostile to human life, Which does seem to track with human attitudes towards it, and a number of physiological adaptations of the native Vulcans.

Tatooine has no open bodies of water of any kind, and the prevalence of moisture farming would indicate that the majority of the ecosphere's water is atmospheric (there may be subterranean aquifers but they would either be insufficient for the needs of even the very sparse populous, or impractically out of reach. Elsewise drills would dot the landscape instead of vapourators.) On the other hand, the are *some* visible clouds, so there's at least a degree of humidity, which means some kind of water cycle from the surface. Indeed, flash floods may be a (very dangerous) thing when one of those clouds actually bursts.

Now Arrakis is as dry as they come. No rain, no clouds that aren't made of dust that'll cut flesh to the bone. Almost all of the surface water has been systematically removed and supressed deep beneath the bedrock over millions of years by the larval sandtrout. For good reason: that shit is both toxic and chemically corrosive to it's adult form (they literally melt and vaporise into blue smoke.) The native Fremen have been so affected by the paucity of moisture that not only does it permeate their culture, it's altered their stock human biology. Fremen *cannot* shed tears. The phenomenon is so rare it's looked at as almost supernatural and perceived with a kind of religious awe. I'd say it'd be up there with walking on the Sea of Galilee or parting the Red Sea, but that would require explain to a Fremen what a sea even is, and assuming they don't just give you a look like you've spent too much time staring at the sun, they'd be more impressed by THAT than anything done to it by some beardy bloke in sandals. The other major adaption the Fremen possess is that their blood is borderline hypercoagulative; when wounded it clots almost instantly, loosing as little moisture as possible.

So what does all this mean? That Arakkis may be the hottest, (probably over the 120°C limit in the deep desert) but the lack of moisture makes the higher temperatures more survivable, although the wildlife will eat you (and the locals may render your corpse for it's water.) Vulcan may support the most life but the humidity (and old radioactive fallout) means that it takes a lot less for things to get unbearable for humans. Also the wildlife will eat you. Tatooine may be the most liveable of the three, provided one stays in shelter at noon and have access to enough water...and stays away from krayt nests and sarlacc pits. Because, you know...they'll eat you.

 

Probably same temperature as Tunisia.

 

OK.
I know how much of a different humidity makes from first hand experience. When we hit our monsoon season the temps drop, but the humidity shoots up, and that is a lot more uncomfortable than the drier, higher temps we hit before it starts. It kind of amazes me at times just how much more uncomfortable just an extra 10% or 15% humidity can make.

 

I wish we had gotten a scene where McCoy or Trip commented on Vulcan being hot but not as hot as the south in the summer.

 

"But it's a dry heat."

 

I grew up in Florida, and drove out to California when I moved here, and it was my first time being anywhere near that far west. I stopped for lunch in Arizona one day and, seeing my dashboard thermometer tell me it was 105° F outside, got out and took a moment to appreciate the whole "It's a dry heat" thing for the first time (aside from opening an oven while cooking or something). It was about fifteen seconds before it lost its novelty and I went inside. Snow, on the other hand, was interesting for a lot longer when I finally experienced it.

 

Opening an oven is a perfect analogy for what it feels like going outside in the summer here. At times it can feel like a literal wall of heat when you go from an air conditioned building to outside.