'Weather' and 'climate' are used interchangeably. They shouldn't be

January 22, 2019 by Jennifer Fitchett, The Conversation
Heavy snow in Washington, DC, is an example of “weather” - not “climate”. Credit: Erik S. Lesser/EPA-EFE

As January 2019 entered its third week, huge swathes of the US are blanketed with snow, and winter storm warnings were in place across several states. US President Donald Trump, who has made it clear that he believes climate change is an overblown hoax, took to Twitter to suggest that "a little of that good old fashioned Global Warming" would be welcome.

Trump has fallen into the same trap that many people around the world do: conflating "" and "". The US's current snow storms and cold snap are an example of weather—they will persist for a couple of days to a few weeks at maximum, but will eventually stop and make way for clear skies and inevitably a warm summer for much of the US.

This confusion is common. So, what is the difference between "weather" and "climate"?

At a very simple level, "weather" refers to day-to-day conditions of the atmosphere—the maximum temperature, the amount of cloud cover, the speed and direction of wind and any precipitation that might occur. "Climate" describes the average atmospheric conditions over many years—the average annual rainfall, the predominant wind direction, or the season in which rain is likely to occur. The World Meteorological Organisation states that calculating a "climate" record requires a minimum of 30 years of data.

But does that mean the rain, sun, wind, hot days and cold nights over the last 29 years is just "weather"? Not really.

Clothing provides a useful analogy in understanding this.

Your weather wardrobe

Weather, in this analogy, can be considered by the clothes that we choose to wear on a given day. I'm writing from South Africa, where January and February are the peak of summer. At this time of year, South Africans are likely to wear shorts, t-shirts, sundresses, sandals or flip-flops and perhaps a sunhat. We are very unlikely to wear a warm winter coat, boots, a scarf or a beanie today.

However, in South Africa's wintertime those clothes would be a good choice – paired with warm trousers, a long-sleeved shirt and in mid-July perhaps even some thermals.

If it is a bit cooler tomorrow, with a chance of rain, we may wear closed shoes and a thin jersey. If it is even hotter we may head to the beach or the swimming pool, in which case our clothing choice for the day would involve a swimming costume and towel. So, what we wear changes day-to-day.

Climate, on the other hand, can be understood as the contents of our wardrobe. This consists of a variety of clothing: both that which suits summer weather and those items which are best worn in winter. Our wardrobe, then, represents all the weather conditions one is likely to face throughout the year, for every year that we live in a particular place.

Place is important. The wardrobe of someone living in Johannesburg, South Africa, is very different to the collection of clothes owned by a resident of Helsinki, Finland. South Africans certainly don't need thermal clothing for sub -20°C temperatures, and Finns have little use for sundresses and shorts (unless, of course, people are heading off on holiday).

The same is true of weather and climate. The conditions experienced at one location necessarily different to those experienced at differing distance to the poles.

Improved understanding

What does this knowledge mean for our understanding of and climate ?

A forecast is what you will see on the televised weather report each night, or on your phone's weather app. It will tell you the minimum and maximum temperatures likely to occur, and the chance of rainfall. It will also include any alerts for extreme events likely to occur in the next 24 to 72 hours. The weather forecast is helping you choose what to wear.

Climate projections, whether derived from regional and global climate models or from statistical trend analysis of fluctuations over past decades, tell us about the anticipated climate in the next few decades to 100 years. These are letting us know, well in advance, that we may need to think about changing the contents of our wardrobe. We perhaps should invest in fewer thermals and thick coats, and more sundresses and shorts.

We might need to buy a more hardy umbrella or raincoat for more frequent use, or perhaps a water tank for our backyard depending on where we live. But, we do not need to spend the contents of our most recent salary on a whole new wardrobe and throw out everything we have overnight – just slowly, over years to decades, plan and adapt.

Explore further: Exercise safely when the weather outside is frightful

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Anonym
1.6 / 5 (7) Jan 22, 2019
This conflating of weather and climate bedevils scientists and non-scientists alike. For example, in Climate Science (tm) 30 years is considered "climate" whereas in geology, a science discipline unconstrained by political or economic considerations, climate is viewed on a scale of tens of thousands of years. The present Ice Age is a million years old. The current "heat wave" began about 15,000 years ago and may have peaked about 8,000 years ago.

Which climate governs: the 30-year cycle or the million-year cycle? Hint: the climate modelers predicted the "end of snow" and disappearance of the arctic ice cap by 2020.
julianpenrod
1 / 5 (7) Jan 22, 2019
It could be mentioned weather is caused by transient conditions, while climate comes from circumstances that are constant, the shape of continents, the make up of the seas, the components in the air, the effects of life, the energy range of sunlight. Only the weather is changing on earth, not the shape of the land, the seas, the effects of life, the characteristics of sunlight, so there is no "climate change".
Too, what if weather is constantly being affected to take on an unnatural form. The simplistic would call that a change in "climate"! But it would only be the result of the weather being acted upon artificially! Abnormal weather is being caused by the government project of doping the atmosphere with weather modification chemicals from high flying jets, producing long, non dissipating vapor trails that can reach from horizon to horizon and last for an hour or more, what has come to be called "chemtrails".
Bert_Halls
3.7 / 5 (3) Jan 22, 2019
@Anonym Fuck you, you lying sack of shit.
and @julianpenrod your stupidity is below contempt.
MR166
1.7 / 5 (6) Jan 22, 2019
Bert the intelligence behind your comments leads me to a deeper understanding of the reasons for the wide acceptance of the AGW hoax.
MR166
1 / 5 (5) Jan 22, 2019
Every time a negative weather event occurs a rash of papers follows linking it to AGCC. The hypocrisy of this article is sickening.
MR166
1 / 5 (4) Jan 22, 2019
AGCC was a very important step in validating climate science. When it was just plan old AGW the science was easily disproved by the lack of warming. You see one can actually measure temperature change. Whereas climate change change can only be measured by statistical analysis which is easily biased as needed by the purveyors of this so called science.
MR166
2 / 5 (4) Jan 22, 2019
At first AGW was supposed to cause more hurricanes. But they had a big problem there because one could actually count hurricanes and the figures did not add up. So they morphed it into more intense hurricanes and vu'a la proof via statistical analysis creating the called for headlines.
antigoracle
2 / 5 (4) Jan 22, 2019
It's ONLY the AGW Cult that use Climate and Weather interchangeably, and deliberately so, to propagate their dogma and feed their ignorant, hungry Chicken Littles.

"Climate" describes the average atmospheric conditions over many years

Again, that "definition" of climate is propagated by the AGW Cult, who continuously move the "many years" value, to generate that "average", so that they can then claim anything outside of it is due to gloBull warming.

Climate is NOT an average. Climate modulates weather in both frequency and intensity. And, being driven, by cycles within cycles within cycles, spanning decades, centuries and millennia, you can expect weather than spans the gamut of intensity and frequency.
aksdad
1.8 / 5 (5) Jan 22, 2019
Trump has fallen into the same trap that many people around the world do: conflating "climate" and "weather".

No he hasn't. He's trolling the climate alarmists with his tweet. Clearly, he's being ironic (making a joke); a point lost on that humorless herd.
Bert_Halls
2.3 / 5 (3) Jan 22, 2019
There's a method to my madness, actually. I intend to make these threads so obviously polluted that phys.org has no choice but to take them down.

Then your festering shit will no longer be on display next to credible scientific articles.

By the way, @MR166, the only reason your mother's not a whore is that wild boars don't have money.
MR166
1 / 5 (3) Jan 22, 2019
"There's a method to my madness....."

Well Mango Bert at least you realize that you are mad. That is the first step in being cured.
ChucktheCanuck
1 / 5 (6) Jan 22, 2019
"plan and adapt" - exactly as we always have. Leave the hysteria to the zealots.
greenonions1
5 / 5 (4) Jan 22, 2019
MR166
You see one can actually measure temperature change
Yep - one can. https://climate.n...erature/
Look at graph 1 in the article MR - the pictures are easier for you to comprehend. Do you have any graphs you can show us that indicate no warming?
Anonym518498
Jan 22, 2019
This comment has been removed by a moderator.
snoosebaum
1 / 5 (3) Jan 22, 2019
before you waste any more time on this BS , the article was published by 'Misha Ketchell'
who wrote this propaganda about 'fake news' . He being a fake newser himself.

https://www.allia...ws-need/
greenonions1
5 / 5 (1) Jan 23, 2019
He being a fake newser himself
It's all so Orwellian - isn't it snoose? Fake newswers accusing others of fake news - but how do we tell the fake news from the real news? Do we ask you snoose? Will you enlighten us? Do you disagree with the scientific understanding of weather vs climate? We see the uneducated on this site all the time. "It was cold in Austin Texas last week - climate change is a hoax!"
greenonions1
5 / 5 (1) Jan 23, 2019
aksdad
Clearly, he's being ironic (making a joke)
The old fall back - right? Say something really stupid - and then say "It was just a joke." The problem for grifters - is that they become surrounded by grifters. Then they form a circular firing squad. So Cohen turns on Trump, and Trump turns on Cohen - etc. etc. etc. Trump, Escobar, Gaddafi, Mussolini etc. - all end up wondering why no one likes them. The problem is the collateral damage.
Anonym
1 / 5 (2) Jan 23, 2019
The distinction is this: if the temp is above normal, it's "climate change;" if temps are below normal, that is "weather."
snoosebaum
1 / 5 (2) Jan 23, 2019
'' Fake newswers accusing others of fake news - but how do we tell the fake news from the real news? ''

we use our brains , a lost art it seems

weather/climate , very simple, even for you , we are one degree warmer [ maybe !] than 1860, no matter the weather
greenonions1
4 / 5 (4) Jan 23, 2019
snooze
we are one degree warmer [ maybe !] than 1860, no matter the weather
More like 1.4 degrees,
http://berkeleyea...2017.png

but really - what is your point in making that stipulation? Are you saying that this is just a small number, so nothing to worry about?

we use our brains , a lost art it seems
It would seem to me that if you had any critical thinking skills - you would realize what a weak response that is. My comment was meant to be facetious - but it is clear to me that 2 people, who both have good brains, can look at the same data - and draw very different conclusions. But I do agree that there is a lack of critical thinking skills - certainly in the U.S. today . Any one who had done any reading on Trump - would never have voted for such a criminal.

netprophet
1 / 5 (3) Jan 24, 2019
In 1989, NOAA said the US had not warmed since 1895 and it was reported in the New York Time. Since then, the NOAA data has been adjusted upwards slightly. However, the Berkeley Earth data set now shows nearly 1C warming during that same period. It is completely untrustworthy.
netprophet
1 / 5 (3) Jan 24, 2019
This is climate.....snow levels on an upward trend over the past 50+ years in spite of the nonsense from government funded climate fraudsters and the media.....https://climate.r...season=1
SteveS
5 / 5 (2) Jan 24, 2019
This is climate.....snow levels on an upward trend over the past 50+ years in spite of the nonsense from government funded climate fraudsters and the media.....https://climate.r...season=1


And what is this then?

https://climate.r...season=2
SteveS
3 / 5 (2) Jan 24, 2019
In 1989, NOAA said the US had not warmed since 1895 and it was reported in the New York Time. Since then, the NOAA data has been adjusted upwards slightly. However, the Berkeley Earth data set now shows nearly 1C warming during that same period. It is completely untrustworthy.


You're comparing global data sets to regional.
netprophet
2 / 5 (4) Jan 24, 2019
Climate fraudsters say extreme weather has increased due to CO2 emissions from your SUV. The reality shows the opposite - a steady decline in the frequency of violent tornadoes. http://diekalteso...eworden/
netprophet
2 / 5 (4) Jan 24, 2019
Of course they are not the same. Climate fraudsters and the media repeatedly blamed all three major Atlantic gulf hurricanes in 2017 on climate but then ignore that worldwide hurricane activity in the same year was more than 20% below the 50 year average.
netprophet
2 / 5 (4) Jan 24, 2019
30 years ago, James Hansen and his ilk turned off the HVAC system on Capital Hill in the middle of August while it was 95 deg and 100% humidity and then predicted that because of CO2 emissions, the US would experience increasing severe patterns of drought. In the ensuing 30 years, two of every three years has been WETTER than normal. Another failed prediction from climate frauds....
netprophet
2 / 5 (4) Jan 24, 2019
In 1988 "scientists" predicted that all 1300 Maldives Islands would be underwater by the end of 2018. Of the 1300 islands, exactly 0 are underwater today. https://www.kured...gallery/
netprophet
2.3 / 5 (3) Jan 24, 2019
Nearly 19 years ago scientists said snowfalls were a "thing of the past". https://web.archi...017.html

Northern Hemisphere fall snowfall trend since 1967 - up from 18.4 million sq km to 20.2
Northern Hemisphere winter snowfall trend since 1967 up from 45.2 million sq km to 46.0
Northern Hemisphere spring snowfall trend since 1967 down from 31.5 million sq km to 28.8

Net Change? NONE.
netprophet
2 / 5 (4) Jan 24, 2019
Yes climate change is supposed to be increasing extreme weather events. Why then do real scientists report none? https://www.clim-...89/2016/
netprophet
2 / 5 (4) Jan 24, 2019
How do climate fraudsters measure arctic ice? By starting in 1979, the peak of arctic sea volume from satellite data and ignoring all satellite data from prior years as published in this IPCC report on page 224...........https://web.archi...r_07.pdf
netprophet
2 / 5 (4) Jan 24, 2019
Global warming theory is after all, merely a theory with little resemblance to reality........https://www.scien...18305030
MR166
1 / 5 (1) Jan 24, 2019
Thanks for the input Prophet. We have slowly morphed from the information age to the disinformation age. Fake news, fake science and fake history is all part of the plan to destroy our system.
greenonions1
5 / 5 (2) Jan 24, 2019
netprophet
In 1989, NOAA said the US had not warmed since 1895 and it was reported in the New York Time
Yep - it was reported in the New York times - https://www.nytim...end.html

Along with this quote from the author of the study -
the findings concerning the United States do not necessarily ''cast doubt'' on previous findings of a worldwide trend toward warmer temperatures, nor do they have a bearing one way or another on the theory that a buildup of pollutants is acting like a greenhouse and causing global warming. He said that the United States occupies only a small percentage of Earth's surface and that the new findings may be the result of regional variations
So what's your point? Denier - cherry picker.
SteveS
5 / 5 (2) Jan 25, 2019
Nearly 19 years ago scientists said snowfalls were a "thing of the past". https://web.archi...017.html

Northern Hemisphere fall snowfall trend since 1967 - up from 18.4 million sq km to 20.2
Northern Hemisphere winter snowfall trend since 1967 up from 45.2 million sq km to 46.0
Northern Hemisphere spring snowfall trend since 1967 down from 31.5 million sq km to 28.8

Net Change? NONE.


The shift in snowfall from spring to fall looks like climate change to me.
humy
5 / 5 (1) Jan 25, 2019
in Climate Science 30 years is considered "climate" whereas in geology, a science discipline unconstrained by political or economic considerations, climate is tens of thousands of years.
Anonym

This is clearly all false. For starters, climate science, just like geology, is not "constrained" by "political or economic considerations". Why should it be? Climate science is just that; the study of climate. It isn't like its a commercial product; the scientists either observe a particular change in the climate or no such change and report the result regardless of its "political or economic considerations".
Also, the totally arbitrary 'long' time period that distinguishes the meaning of the words 'climate' from 'weather' isn't well defined in ANY science, and that INCLUDES climate science. That arbitrary 'long' time period varies and its length chosen depends on the context and what is currently considered to be most convenient. Why 30 and not 31 years?

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