# www.felsius.app

> AI-optimized mirror of www.felsius.app containing 24 pages totalling 17,086 words of clean markdown content, structured data, and semantic HTML. Original source: https://www.felsius.app/. Last updated: 2026-04-30T22:57:27.961Z.

Each page is available as HTML (with JSON-LD structured data) and Markdown (text-only, ideal for LLMs and RAG).

## Homepage

- [Never google “what’s 68°F in °C?” again](/site-root.html): Felsius is the weather app that shows Celsius and Fahrenheit at the same time — no switching settings, no converting. Built for expats, travellers, and mixed-unit households. (532 words)

## Articles & Blog Posts

- [What Is Room Temperature (and Why No One Agrees)?](/learn/what-is-room-temperature/index.html): Room temperature is usually defined as 20–22°C (68–72°F), but the exact value varies by country, context, and purpose. Here's why no one can agree. (1,148 words)
- [Privacy & Terms](/privacy/index.html) (1,227 words)
- [Why Temperature Numbers Don't Map Cleanly to Comfort](/learn/why-temperature-numbers-dont-map-to-comfort/index.html): A temperature number tells you where you are on a scale. It doesn't tell you how it will feel. Here's why the same number can feel completely different depending on context. (713 words)
- [The Celsius & Fahrenheit Field Guide](/learn/index.html): Articles to help you build intuition around Celsius and Fahrenheit for expats, travellers, and
  families. No formulas. Just clarity. (561 words)
- [How Cold Is 0°C, Really?](/learn/how-cold-is-0c/index.html): 0°C is 32°F – the freezing point of water. But what does it actually feel like to stand outside at 0°C? Here's what changes at freezing and what to expect. (644 words)
- [Why Converting Temperatures All Day Is Mental Overhead](/learn/why-converting-temperatures-is-mental-overhead/index.html): Every time you convert a temperature in your head, you're spending cognitive resources. For people who do this daily, the cost adds up. Here's why it matters and what to do about it. (649 words)
- [What Does 20°C Actually Feel Like?](/learn/what-does-20c-feel-like/index.html): 20°C is 68°F. Outdoors it's a light jacket day. Indoors it's on the cool side. Here's why it's one of the most misread temperatures by people using Fahrenheit. (754 words)
- [How Cold Is 5°C, Really?](/learn/how-cold-is-5c/index.html): 5°C is 41°F. It's properly cold – the kind where damp air bites and a jacket isn't optional. Here's what 5°C actually feels like and how humidity makes it worse. (654 words)
- [Why Most Weather Apps Make Temperature Harder Than It Needs to Be](/learn/why-weather-apps-make-temperature-harder/index.html): Most weather apps were designed around a single assumption: one unit, one person, one country. Here's why that assumption creates friction for millions of daily users. (657 words)
- [Why Americans Struggle With Celsius (and Why That's Normal)](/learn/why-americans-struggle-with-celsius/index.html): The US uses Fahrenheit. The rest of the world uses Celsius. Americans who travel or move abroad often find the switch genuinely disorienting – and that's not a personal failing. (683 words)
- [Why Celsius and Fahrenheit Feel So Different](/learn/why-celsius-and-fahrenheit-feel-different/index.html): Celsius and Fahrenheit don't just use different numbers – they shape how we feel about temperature. Here's
  why switching between them is so disorienting. (846 words)
- [How Hot Is 35°C, Really?](/learn/how-hot-is-35c/index.html): 35°C is 95°F. It's genuinely intense heat – not just warm. Here's what 35°C actually feels like outdoors, whether to stay inside, and what your body does to cope. (584 words)
- [How Hot Is 40°C, Really?](/learn/how-hot-is-40c/index.html): 40°C is 104°F. This is extreme heat – a threshold where the human body starts to struggle. Here's what it actually feels like and what to know before going outside. (617 words)
- [Why −40° Is the Same in Celsius and Fahrenheit](/learn/why-negative-40-is-the-same/index.html): At −40 degrees, Celsius and Fahrenheit are identical. Here's why the two scales meet at this one point – and why it's easier to understand than you'd think. (555 words)
- [Living Between Celsius and Fahrenheit](/learn/living-between-celsius-and-fahrenheit/index.html): Some people spend their lives switching between two temperature scales. Here's the hidden cognitive cost of that – and what it means to finally have both at once. (649 words)
- [Why Fahrenheit Feels More Precise (Even When It Isn't)](/learn/why-fahrenheit-feels-more-precise/index.html): Fahrenheit feels more granular than Celsius – but granularity isn't the same as precision. Here's why people defend Fahrenheit, and what precision means. (604 words)
- [How Hot Is 25°C, Really?](/learn/how-hot-is-25c/index.html): 25°C is 77°F – mild warmth, universally pleasant. Here's what 25°C actually feels like, why sun vs shade matters, and when it stops feeling comfortable. (582 words)
- [Why "Feels Like" Temperature Often Makes Things Worse](/learn/why-feels-like-temperature-makes-things-worse/index.html): The "feels like" number in weather apps sounds helpful but often creates more confusion. Here's what it actually measures and when to ignore it. (608 words)
- [Why Build a Weather App That Shows Celsius and Fahrenheit?](/learn/weather-app-celsius-fahrenheit/index.html): Most weather apps make you choose a unit. Felsius shows both Celsius and Fahrenheit together – no toggling, no converting, no friction. Here's why that matters. (624 words)
- [How Hot Is 30°C, Really?](/learn/how-hot-is-30c/index.html): 30°C is 86°F. It's summer territory, but humidity changes everything. Here's what 30°C actually feels like and why Fahrenheit intuition often gets it wrong. (620 words)
- [Why We Misjudge Temperature When Switching Units](/learn/why-we-misjudge-temperature/index.html): When you hear a temperature in an unfamiliar unit, the feeling doesn't land. Here's the psychology of why converting temperature is harder than it looks. (660 words)
- [What to Wear at Any Temperature](/learn/what-to-wear/index.html): Slide to any temperature and see what to wear. Works in both °C and °F. An interactive guide for expats, travellers, and anyone switching between temperature scales. (1,322 words)
- [How Cold Is 10°C, Really?](/learn/how-cold-is-10c/index.html): 10°C is 50°F. It's cooler than most expect, especially with wind. Here's what 10°C actually feels like and when a proper jacket stops being optional. (593 words)

## Resources

- [Full Page Index](/index.html): Browse all cached pages with rich metadata
- [About This Cache](/content/about.html): Methodology, technical details, and usage guidelines
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