Quick Answer: –40°C = –40°F
Many people ask: “Which is colder: –40°C or –40°F?“
The answer is simple: they are exactly the same.
Yes, at –40 degrees, the Celsius and Fahrenheit scales intersect. It’s the one point where both temperature systems agree.
Where in the World Does It Reach –40?
Regions that commonly experience –40 include:
| Location | Country | Notes |
|---|---|---|
| Yakutsk | Russia | One of the coldest cities on Earth |
| Yellowknife | Canada | Winter temperatures reach –40 easily |
| Fairbanks | USA (Alaska) | Often hits –40°F during winter |
| Norilsk | Russia | Bitterly cold Siberian winters |
| Ulaanbaatar | Mongolia | Harsh continental climate |
At –40 degrees:
- Boiling water freezes mid-air.
- Steel becomes brittle.
- Frostbite can occur in minutes.
- Even your eyelashes can freeze.
It’s not just cold—it’s painfully dangerous if unprepared.
Why Do Celsius and Fahrenheit Meet at –40?
Here’s the math:
To convert:
(°C × 9/5) + 32 = °F
Let’s try –40:
(–40 × 9/5) + 32 = –72 + 32 = –40°F
So:
–40°C = –40°F
It’s a unique crossover point between the two temperature scales.
Celsius vs Fahrenheit Conversion Table
Use this chart to better understand the temperature difference:
| Celsius (°C) | Fahrenheit (°F) | Freezing Notes |
|---|---|---|
| –40°C | –40°F | Arctic survival level |
| –20°C | –4°F | Deep freeze |
| –4°C | 24.8°F | Cold, but above freezing |
| 0°C | 32°F | Freezing point of water |
| 40°C | 104°F | Very hot (e.g., desert) |
You’ll often see “40°C” on clothes labels or washer settings.
Here’s what it means:
- 40°C = 104°F
It’s warm water, great for:
- Everyday clothes
- Light stains
- Delicates needing a warm cycle
So no, 40°C is not hot, just comfortably warm for fabrics.
What About –4°C? Is That Freezing?
Yes! –4°C is below freezing.
Water freezes at 0°C, so at –4°C:
- Roads can be icy.
- Frost forms.
- Pipes can freeze if exposed.
In Fahrenheit: –4°C ≈ 24.8°F
How to Convert °C to °F (and Back)
Quick Formulas:
- Celsius to Fahrenheit: (°C × 9/5) + 32 = °F
- Fahrenheit to Celsius: (°F – 32) × 5/9 = °C
FAQs
Q: Which is colder: –40°F or –40°C?
A: They’re exactly the same.
Q: Is –4°C below freezing?
A: Yes. It’s about 24.8°F and water will freeze.
Q: Where does it get to –40 in real life?
A: Northern Canada, Siberia, Alaska, and Mongolia.
Q: Why do Celsius and Fahrenheit meet at –40?
A: It’s the point where both temperature formulas give the same result.
Q: What does 40°C mean on a washer?
A: It means 104°F—warm, but not hot.
Conclusion:
–40°C and –40°F are the same, but that doesn’t make them any less extreme. Now you know how it feels, where it happens, and how to read it—whether it’s outside your window or on your washing machine.