18 March 2015

Why Dennis Mersereau at Gawker is Wrong About Fahrenheit Being A Better Temperature Scale

Posted by Dan Satterfield


BBC Weather showing U.S temps as the rest of the world sees them.

BBC Weather showing U.S temps as the rest of the world sees them.

I enjoy Dennis Mersereau’s pieces on Gawker, and I suspect his piece (touting the superiority of the OLD Fahrenheit scale) was covertly designed to get a thousand ugly comments from those of us who live metrically, and apparently it worked. Now, I suspect that most of Fahrenheit’s dwindling number of supporters are the type who have trouble remembering if 0.04 is 4 tenth’s or 4 hundredth’s, and are of the mind that Celsius is a UN plot for a one world “Commie” government. Let’s leave those folks out of it, and just look at the issue dispassionately.

Point One
I’ll start making my case for Celsius with a quote right from the beginning of Dennis’s post: “”Celsius is the proper form of measurement,” they haughtily trumpet, “because everyone else uses it.” Everyone else is wrong.” 

So, the entire rest of the world is wrong, and the lone remaining country still using the old temperature scale is right. Think about that for a moment, and you start to see that it seems a bit smug to think that we know better than everyone else. The reason we have such things as standard time, and the metric system is because it’s important that everyone agrees on the same form of measurement.

Failure to do this can actually be costly, and the fate of NASA’s Mars Climate Orbiter is a perfect example; quoting NASA JPL here: “The peer review preliminary findings indicate that one team used English units (e.g., inches, feet and pounds) while the other used metric units for a key spacecraft operation. This information was critical to the maneuvers required to place the spacecraft in the proper Mars orbit.”. The rest of the story can be summed up using another quote from James Taylor- “Sweet dreams and flying machines, in pieces on the ground”.

In the days when you had to call an operator (and pay a weeks wages) to make a call to London, and only the very rich could afford to fly to Europe for a few days, it really didn’t matter so much if we used one system, while the rest of the world used another. Those days, however, are long gone. My new iphone made it from China, where it was made, to my door in about 72 hours, and if you want to imitate a Sardine and pay for the toilet, Ryan Air says they will fly you to Europe for 15 quid (20 euros). We live in a world economy where having a set standard for measurements matters.

Almost all internal weather data is now in Celsius, and the aviation observations made each hour at local airports in the U.S. already use Celsius. The NWS converts this data to the OLD Fahrenheit system before distributing it to the public. I really hope that my pilot, when figuring out the weight and balance before my next plane ride, doesn’t make an error like the engineers who worked on the Mars Climate Observer. I’d hate to think that our pilot would think we need 2,000 meters of runway* when in reality we need 2500, especially if the runway is only 2400. Confusing Celsius and Fahrenheit could make that happen, giving everyone on board a bad day.

Point TWO (Yes this is looking like it will be a long post.)


The NWS Weather balloon data from Sterling,Virginia for 0 GMT Wed. March 18. Pressure is in metric and so is temperature. Wind is in knots still which lingers for aviation reasons, but will eventually be km/hour.

The NWS Weather balloon data from Sterling,Virginia for 0 GMT Wed. March 18. Pressure is in metric and so is temperature. Wind is in knots still which lingers for aviation reasons, but will eventually be km/hour.

Dennis goes on to make the claim that “Fahrenheit gives you almost double—1.8x—the precision* of Celsius without having to delve into decimals, allowing you to better relate to the air temperature. Again, we’re sensitive to small shifts in temperature, so Fahrenheit allows us to discern between two readings more easily than Saint Celsius ever could.

As was pointed out by a commenter, he confuses accuracy with precision here. Take a look at the specs on your trusty digital thermometer you got at Wal-Mart, and you will likely see that it’s accuracy is rated at 1C. That’s right, it’s accurate to one degree CELSIUS. Not a big deal actually, because you almost certainly cannot tell the difference between 45 and 46 degrees Farhenheit, but you can tell a difference between 6 and 7C (Well I can, but my wife says it’s because I’m an uber weather geek). The point here is that the higher precision of the Fahrenheit scale is really worthless, and the thermometer attached to your house or car cannot measure with an accuracy that matches the precision of the scale. In other words, I really have no use for a thermometer that measures in thousandths of a degree if the thermometer has an accuracy of 2 degrees.

Point Three

Dennis says “Outside of the polar regions and deserts, the typical range of temperatures stretches from -20°F to 110°F—or a 130-degree range—with daily readings clustered even tighter for most of us. On the Celsius scale, that would convert to -28.8°C to 43.3°C, or a 72.1-degree range of temperatures.” 

First of all, for most people on the planet, the temperature is between -25 and 35C, or a 60 degree range in temperature, and I suspect about 80% of the planet would fall into a 35 degree range for much of the time at any one location. He converts his most likely Fahrenheit temperatures to Celsius and comes up with -28.8C and 43.3C. Oh, so confusing! Now, let’s do it the way the ENTIRE rest of the world would do it, and convert from -25C to 35C into Fahrenheit. We get -13.0 and 95.0F. The point here is that Dennis looked at it from someone used to Fahrenheit and got a decimal number that looks complicated. The person used to Celsius would do the same in reverse and convert to Fahrenheit, possibly getting a weird number like 47.4 degrees F! If you are thinking “So what!” then I made my point.

Point 4 (being the best of all)



Rivers do strange things when the air gets colder than 0C. Dan's pic of the Choptank River in Maryland in February.

Rivers do strange things when the air gets colder than 0C. My pic of the Choptank River in Maryland a couple of weeks back.

Strange things happen on our planet when the temperature reaches the freezing point of water at standard pressure. Lakes freeze, roads sometimes get very icy and Boston gets buried in ice crystals,so a case can be made that freezing is by far the MOST important temperature. Let’s make it an easy number to remember, like say ZERO! If the temp. is below zero, watch out for bad things to happen. Above zero, your OK. What’s so special about 32?

To conclude, all of the objections I hear to Celsius can be traced back to the fact that people are not used to it. Someone used to Celsius would have the same objections to Fahrenheit (and my European friends do indeed say exactly the same about  the old scale used in America). In this age of anti science where U.S. Senators think a snowfall disproves basic physics, converting to metric might just be what this country needs to get our education system back on track.

Here’s an Idea


My best friend lives in Wrexham, and I've driven through this roundabout several times.

My best friend lives in Wrexham, and I’ve driven through this roundabout several times.

Let’s start with metric units only from kindergarten on up, and we would be doing our children a real favor, because they will live in a world that is even more interconnected than we do today. While we are at it, let’s pick up a few other ideas the rest of the world uses, like roundabouts instead of traffic signals. Do you know how much money you waste in gas every year sitting at stop lights that use 1920’s timer technology, when you could have slowed around a corner and merged with any oncoming traffic and been on your way?? Think of how much less pollution would be in the air!

Yes, well that’s a whole other blog post, but when I become the head of that one-world Commie government, every timed traffic signal will be outlawed.. Ok I’m beginning to rant….

 * The runway needed to take off is dependent on weight and the “density altitude”, which in itself is related to temperature.