About Canicular
What is Canicular?
Canicular is a small, independent website built around six free calculators for heat and weather questions: the Dog Days of Summer Calculator, the Heat Index Calculator, the Humidity Comfort Calculator, the Sunrise & Sunset Calculator, the Temperature Converter, and the UV Index Calculator. Alongside the tools there’s a blog, a set of reference guides, and the Heat & the Elements Museum, which we describe below. The site is funded by advertising, not by subscriptions or selling data.
Who is it for?
Anyone trying to make a quick, sensible call about a hot day — whether to push through a run in a heatwave, how strong the sun will be before a beach afternoon, how muggy it’s actually going to feel, or simply what a temperature in Celsius means in Fahrenheit. Each tool asks for a couple of numbers or a date and gives a plain-language answer in seconds. No account, no email required.
How do the calculators actually work?
Each one runs a specific, disclosed method rather than a black box. The Dog Days calculator checks whether a date falls inside the traditional July 3–August 11 window and how far through it you are. The Heat Index calculator uses the U.S. National Weather Service’s heat index regression to turn air temperature and humidity into an apparent (“feels like”) temperature and a risk category. The Humidity Comfort calculator derives a dew point from temperature and relative humidity and maps it to a plain comfort label, from dry to oppressive. The Sunrise & Sunset calculator estimates day length and sunrise/sunset in solar time from your latitude and the day of year — it’s an approximation, not corrected for time zone or elevation. The Temperature Converter applies the standard conversion formulas between Celsius, Fahrenheit, and Kelvin. The UV Index calculator takes a UV reading you enter and returns its risk category, a rough time-to-sunburn estimate for fair skin, and a suggested sunscreen SPF.
Where do the numbers and formulas come from?
We rely on published, widely used references rather than inventing our own math: the National Weather Service heat index equation, standard dew-point approximations, basic solar-geometry formulas for day length, exact unit-conversion arithmetic for temperature, and the standard low-to-extreme UV risk scale used by weather services worldwide. The Heat & the Elements Museum’s entries, images, and facts are drawn from Wikipedia and Wikimedia Commons and linked back to their sources.
Is this medical, safety, or weather advice?
No. Everything on Canicular is general informational and educational content, not professional medical, safety, or meteorological advice. Results are estimates based on the numbers you enter; your actual risk depends on your health, activity, location, and the real conditions at the time. In extreme heat, sun exposure, or any medical emergency, always seek professional help and follow official advisories from a source like the National Weather Service.
Are the tools really free?
Yes. All six calculators are free, with no signup and no paywall. The site is supported by on-page advertising, which is what keeps the tools free to use.
What’s the Heat & the Elements Museum?
It’s a set of galleries about the Sun and sky, heat waves and wildfires, the inventions people have used to cool down, and the plants and animals that thrive in the hottest places on Earth. It sits apart from the calculators — it’s a reading experience, not a tool — and every entry is sourced from Wikipedia and Wikimedia Commons rather than written by us.
Is Canicular affiliated with the National Weather Service, Wikipedia, or any other organization?
No. Canicular is an independent site. We reference public formulas, standards, and sources because they’re accurate and well documented, not because we’re endorsed by or connected to the organizations that publish them.
Who runs this site?
Canicular is run as a small, independent property, not a staffed company with offices or a support desk. If you spot an error, have a question, or want to suggest something, the contact page is the way to reach us.