das  Celsius

B2

Estimated CEFR level.

/ˈt͡sɛlziʊs/

🌡️ What does "das Celsius" mean?

Das Celsius refers to the unit of measurement for temperature on the Celsius scale. It is almost always used in conjunction with "Grad" (degree): das Grad Celsius (symbol: °C).

It is named after the Swedish astronomer Anders Celsius.

Although "Celsius" itself is a proper noun, the unit of measurement is treated grammatically as neuter, hence das (Grad) Celsius.

🚨 Important: You don't say *"ein Celsius"* (one Celsius), but rather *"ein Grad Celsius"* (one degree Celsius) or state the temperature directly (e.g., *"Es sind 20 Grad Celsius"* - It's 20 degrees Celsius, or colloquially *"Es sind 20 Grad"* - It's 20 degrees).

📐 Grammar of "das Celsius" in Detail

"Celsius" itself is usually not declined. Instead, it functions as part of the unit *"Grad Celsius"*. The declension applies to *"das Grad"*. Since "Celsius" acts like a postposed proper noun or an apposition, it mostly remains unchanged.

Declension of "das Grad Celsius" (Singular)

Declension of "die Grad Celsius" (Plural)

💡 Note: In the plural, *"Grad Celsius"* often remains unchanged, especially after numbers (e.g., *"20 Grad Celsius"*). The form *"Grade"* is formally correct but less common in this context (*"20 Grade Celsius"*).

📝 Example Sentences

• Die Temperatur erreichte heute 30 Grad Celsius. (The temperature reached 30 degrees Celsius today.)
• Der Gefrierpunkt von Wasser liegt bei null Grad Celsius. (The freezing point of water is zero degrees Celsius.)
• Wir messen die Temperatur in Grad Celsius. (We measure temperature in degrees Celsius.)

🤔 How to use "Celsius"?

"Celsius" is used almost exclusively in the context of temperature measurements. Here are typical use cases:

• Weather reports: *"Morgen erwarten wir Höchstwerte um 25 Grad Celsius."* (Tomorrow, we expect highs around 25 degrees Celsius.)
• Science & Technology: *"Die Reaktion findet bei 100 Grad Celsius statt."* (The reaction takes place at 100 degrees Celsius.)
• Cooking & Baking: *"Den Ofen auf 180 Grad Celsius vorheizen."* (Preheat the oven to 180 degrees Celsius.)
• Medicine: *"Die normale Körpertemperatur liegt bei etwa 37 Grad Celsius."* (Normal body temperature is around 37 degrees Celsius.)

Context: "Celsius" is the most common temperature unit in Germany and many other countries worldwide, unlike Fahrenheit (mainly used in the US) or Kelvin (used in science).

Comparison: While people often just say *"Grad"* colloquially (*"Es sind 30 Grad"* - It's 30 degrees), the full and precise form is *"Grad Celsius"*.

🧠 Mnemonics for "das Celsius"

For the article (das): Think of das Maß (the measure) or das System (the system). Both are neuter nouns, just like das (Grad) Celsius, which measures something within a system.

For the meaning (temperature unit): Imagine Anders Celsius feeling us-ually cold at 0 degrees Celsius. Linking the name to the zero point helps remember it's about temperature.

🔄 Synonyms & Antonyms

⚠️ Similar terms: Be careful not to confuse "Celsius" with names like "Celsus" (a Roman encyclopaedist).

😂 A Little Joke

Warum ist es im Winter gut, Mathematiker zu sein? Why is it good to be a mathematician in winter?

Weil man dann viele Grad hat, auch wenn es Minusgrade Celsius sind! Because then you have many degrees (Grad also means degree/rank), even when it's minus degrees Celsius!

📜 Poem about Temperature

Ob Sommerhitze, Winters Kält',
(Whether summer heat or winter's cold,)
die Zahl, die uns die Wärme erzählt,
(The number that tells us the warmth,)
auf Thermometern, groß und klein,
(On thermometers, big and small,)
ist oft in Grad Celsius, so muss es sein.
(Is often in degrees Celsius, it must be so.)
Von null bis hundert, Wasser misst,
(From zero to hundred, water measures,)
wie heiß, wie kalt der Tag heut ist.
(How hot, how cold the day is today.)

🧩 Riddle Time

Ich habe Grade, doch kein Diplom,
(I have degrees, but no diploma,)
bin nach 'nem Schweden benannt, bekannt in Rom,
(I'm named after a Swede, known in Rome,)
in Berlin, Paris, fast überall auf der Welt.
(In Berlin, Paris, almost everywhere in the world.)
Ich messe, wie warm es ist oder wie kalt es fällt.
(I measure how warm it is or how cold it falls.)

Was bin ich? (What am I?) ... Die Celsius-Skala (oder Grad Celsius) / The Celsius scale (or degrees Celsius)

🌐 More Interesting Facts

Namesake: Anders Celsius (1701–1744) originally proposed a scale where 100 degrees was the freezing point and 0 degrees the boiling point of water. This was later reversed.

Definition: Today, the Celsius scale is defined via the Kelvin scale. 0 degrees Celsius corresponds to 273.15 Kelvin. The zero point of the Celsius scale (0 °C) is defined as the freezing point of water at standard pressure, and 100 °C as its boiling point.

Symbol: The official symbol is °C.