Temperature is measuring how warm or cold something is, such together the external air temperature, your body temperature, temperature the water because that cooking, boiling, washing, etc.

You are watching: How cold is 30 degrees celsius

So, is the cold or hot when the temperature estimate says it will certainly be 5 degrees or it will certainly be 30 degrees? What temperature walk water freeze at? Or boil at? What temperature is comfortable for your living room?


Using the modern Celsius device of temperature measurement, us can quickly determine how hot or cold it is. It was likewise known as Centigrade. This is because it is based upon the freezing and also boiling points of water with 100 degrees in between those temperatures.

The main SI unit the temperature is the kelvin, which steps absolute temperatures. But, because that our everyday usage, we usage Celsius i beg your pardon is directly related to kelvins. That is collection so that pure water freezes in ~ zero levels Celsius and also boils in ~ one hundred degrees Celsius.

This is a really easy system to discover as these two marker points space so basic to remember:

Freezing at 0 °C

Boiling at 100 °C

And v 100 degrees in between those points, we can specify temperatures utilizing 1 or 2 digit confident numbers. As soon as the temperature is negative, i.e. Listed below 0 °C, then we recognize that that is therefore cold the water will freeze. Water will always be ice listed below 0 °C, liquid from 1 come 99 °C, and steam from 100 °C upwards.

Here is a table reflecting some guidelines regarding Celsius temperatures:

Temperature °CWhat could be at this temperatureHow that feelsOther point out of interest

-30 (that is 30 degrees listed below zero)

Ice, freezer

Very cold if friend are outside in this temperature, unbearable come most




Very cold still however bearable if in too many of warmth clothes



Water freezes, ice cream melts


Typical coldest median temperature for UK in winter




Water has its smallest volume in ~ this temperature*





20Room indoorsWarm
25Warm roomWarm come hot
Typical preferably temperature for British summer
30Hot dayFeeling hotTypical temperature for hotter countries


Body temperature

Very hot

This is the average human body temperature

40Washing an equipment setting for clothing for regular washVery hot
If you are external in this temperature you will certainly feel hot, but more so if humidity is high.If your interior body temperature will this level you room in risk of death.
50Extremely hotNot numerous places get this high in temperature, and this heat you would require to discover shade, drink water and stay cool.
60Washing machine setting for warm wash
Too warm to live inMost bacteria dice at this temperature
90Washing machine setting because that hottest washToo hot to live inHumans cannot survive such high temperatures
100Water boils in the kettle

Water turns to steam
1000Lava native a volcano

1535Melting allude of iron


15 000 000

Core of the Sun

*Note the water broadens as its temperature increases over 4 degrees, and also as it goes colder listed below 4 degrees. That volume will certainly be in ~ its smallest at 4 °C. This is vital to remember once freezing water in the icebox or freezer, together the water will undoubtedly rise in volume as it freezes, and the colder it gets, the enlarge the ice gets. Therefore remember not to put water right into a bottle that will be in the freezer for an ext than a minute or so, as the water inside will expand and break the bottle.

If you need to work in warm conditions, here are guidelines for rest durations needed:

TemperatureRest period (per hour that work)

30 to 32 ºC

10 minutes

32 to 35 ºC

15 minutes

more than 35 ºC

at least 30 minutes

Remember that when you view a weather estimate on TV, in a newspaper or top top the radio, that anything indigenous 20 degrees upwards is walk to it is in warm, above 25 degrees is hot, over 30 degrees is an extremely hot. Listed below 20 is cool, listed below 10 degrees is cold, and also below zero degrees way that it will certainly be icy outside as the water will certainly freeze and also it will certainly feel very cold outside.

Kelvin (for the an ext scientific among us)

The kelvin (symbol: K) is the SI unit of temperature, and is among the seven SI base units. That is defined by 2 facts: zero kelvin is pure zero (when molecular activity stops), and one kelvin is the portion 1/273.16 that the thermodynamic temperature the the triple allude of water (0.01 °C). The Celsius temperature range is now defined in terms of the kelvin.

The kelvin is named after the british physicist and also engineer wilhelm Thomson, 1st Baron Kelvin. Thus we have one more metric unit named after a brother person. Many metric units are not international at all, unequal °F i beg your pardon is Foreign! The degree Celsius (°C) is named after the swedish astronomer Anders Celsius (1701–1744) yet as that is now characterized in regards to the kelvin, that is much more British than Fahrenheit, called after a German scientist.

The native kelvin as an SI unit is effectively written v a lowercase k (unless in ~ the beginning of a sentence), and is never ever preceded through the words degree or degrees, or the price °, unequal Celsius. This is since Celsius is a scale of measurement, vice versa, the kelvin is a unit the measurement.

See more: Difference Between Baseball And Football Cleats And Baseball Cleats

The freezing suggest of water, together we recognize from what we check out above, is 0 °C, and also 0 °C = 273.15 K. For every increase by 1 °C the temperature likewise increases by 1 K. For this reason 0 K = -273.15 °C, 100 K = -173.15 °C, 273.15 K = 0 °C, and also the boiling point of water is 373.15 K (100 °C).