Living in the US means, from time to time, rejecting things French.  This includes but is not limited to French fries, French dressing, and the decimal system of weights and measures.  Damn, those French are busy beavers.

Since we tend to remain obtuse in matters Celsius, it can be tricky to understand — without resorting to a Web tool for translation — what the current temperature as measured in the C entails.

Let this simple lesson provide a useful framework.

Famously, water freezes at zero Celsius and water boils at one hundred Celsius.  (This is for sea level at any rate, but your elevation changes the numbers for both systems so let’s ignore that for this discussion.)  These two C values are not all that useful in a day-to-day sense.

Don’t get me wrong, if you remember zero is freezing it’s easy to understand the difference between 5 ° and -5 ° and what the roads are likely to be like.  Sure, that’s useful.  But it really ends there.  Ok, yeah, zero is thirty-two.  Yay!

But how many even remember that water boils at 212 °?  It doesn’t often come up in casual conversation and it’s never come up in the weather report.

So, to the lesson.

Remember these two numbers:  twenty and thirty.

That’s it.  If you can remember those two numbers Celsius (centigrade) will suddenly make enough sense in any context as to be useful in a day-to-day sense.

Let me explain.  You’ll see the simplicity.

Twenty is sixty-eight and thirty is eighty-five.  That is the full range of human comfort, that ten degree span.

20 ° C = 68 ° F

30 ° C = 85 ° F

Now you see the structure of what matters.  If it’s 20 ° and dropping (or lower) you know you’ll need to bundle yourself appropriately.  If it’s 30 ° and rising (or higher) you know you’ll need to keep to the shade and carry iced drinks from shaded spot to shaded spot.

That’s it.  That’s the entire lesson.  From twenty to thirty is where human comfort lives.  Now you know.