Yes. Though allowances can be made if someone thinks you are Canadian.
Don’t say 27 degrees though - make sure you note it’s Celsius or people are going to be really confused.
Start slow, and use metric where some Americans already use metric. For example, people know what a 2-liter bottle looks like, and I think a lot of people already know a standard wine bottle is 750 ml, so I think referring to beverage bottle sizes in ml or liters is more acceptable & understandable than using kilometers.
Oh, cool, I’m glad to see others use time to communicate driving distance. I’d been told that was a DFW thang. But giving miles/km doesn’t really communicate what I actually want to know: how long is it gonna take & what time do I gotta leave?
Concur that for most of the U.S. it’s mostly drug dealers that know metric (and can convert easily between systems in their heads) or uh, so I heard.
Side question.
I appreciate metric. Especially in cooking grams and liters are so much easier.
I don’t get celcius. Other than being less precise and having 0 and 100 corrospond to freezing and boiling… What’s the value?
I don’t have a horse in this race but…
…Surely this is just a sad reflection on Americans who are not drug dealers? 
j
No one’s going to believe you’re Canadian if you just say it’s 27C to an American audience. To be authentically Canadian you’d have to say something like, “It’s 27 degrees - I’m sorry, 27 Celcius that is. I’m not sure what that converts to in Fahrenheit.” Without the “sorry” part he’ll just sound like a pretentious twit. 
Bah! I go with “yes.” We don’t want no stinkin’ metric here. The commies have been trying to get us to switch for 40 years. Sure, they snuck up on us with the two liter bottle thing, but no more!
I’m shocked by this post. The correct term is “pretentious twat”.
The value in a scientific context is that Celcius maps onto Kelvin very easily. The value in day to day life is less significant. However, the “less precise” thing is silly since decimal points exist (Celcius thermostats almost always operate in .5 degree steps, for example), and in a climate like mine 0 corresponding to freezing is actually of significant value. But yeah, in outside of scientific applications the superior temperature scale is the one you’re accustomed to.
I used to work with a guy who was an alcoholic who would actually estimate driving time in beers.
On the other hand, if people *already *think you’re a pretentious twit (and don’t think they don’t 
), you might as well go ahead and use sensible units on them.
Less precise? 
All scales/measurements are always as precise as you need them to be.
I’ll do some things in metric.
2 liters of soda, 9mm rounds, grams of cocaine, of course I’m not converting that stuff to imperial just because this is America.
Estimating line-of-sight distances under 300 meters… I’ll always do that in meters because that’s the only way I ever learnt how to do it (thanks Army!) Doesn’t come up that often, though.
Apart from that… I’m all for the US converting to metric, but it will only at gunpoint. An individual grassroots action would be kind of douchey.
You think it’s more valuable that 0 was pegged to the freezing point of salt water and 96 is human body temperature because the difference is a power of 2 from the freezing point of ice, but then actually it ended up being 98 for some reason, and 100 doesn’t really mean anything?
I mean literally that’s what Fahrenheit is.
Or, in metric, centiminutes.
Why does it matter? Why does the value of a measuring scale depend on what it’s “pegged to”?
But if it does, how useful is it that a meter is defined as the length of the path traveled by light in a vacuum in 1/299792458 of a second?
You would love Puerto Rico, speed limits are in M/H but distances are in KM
Definitely not a DFW regionalism. I grew up in Central Illinois, now live in Southeastern Missouri, everyone I’ve known has always given driving “distance” in time.
In fact, to hear foreign YouTubers tell it, all of us Americans do it.
No, the value is that it’s what we are used to. I see the value in going through the struggle to mentally adjust to metric, it’s a more useful and in many ways easier to use system. But I don’t know why 30 degrees is better than 86. The scientific reason of mapping to Kelvin makes sense, but doesn’t really effect my life.
You will probably get the opposite reaction that I get when i use American up in Canada. Have no use for the metric system and as an American, the only time you should be using Metric is when buying drugs and Ammo. Other wise its like getting a hooker and only wanting to cuddle.