How to Read a Climate Graph
LOOKING FOR AN EASY-TO-UNDERSTAND GUIDE ON HOW TO READ A CLIMATE GRAPH?
You’ve come to the right place!
Climate graphs are extremely useful to geographers and scientists. They provide annual information about the weather patterns of a particular location and can be used to give an indication of future rainfall and temperature levels.
They are pretty simple to read – once you get the hang of it! This blog post will take you through everything you need to know about climate graphs.
What is a climate graph?
Climate graphs are sometimes referred to as climographs. They are single graphs which give the overall weather of a specified location over a 12-month period. This large time span means they can’t show extremes in daily temperature but seasonal changes can be shown clearly.
The layout of a climate graph is typically always the same, making use of both a bar and line chart.
Along the bottom of the graph, the 12 months of the year will be detailed from January to December.
The left vertical axis will have a scale of either centimetres or inches. The bars on the graph will be the average measurement of the precipitation that has fallen each month. It is standard that the bars will be blue in colour. This will serve as a reminder that they measure water levels.
The right vertical axis will represent temperature. This scale is typically in degrees Celcius or Fahrenheit. Dots will plot out the measurement of the average temperature for each month. These will be connected to form a line graph. More often than not, the gradient will be red – a signal that this is a measurement of temperature. THINK – the liquid inside a thermometer is often red!
Let’s take a look at a climate graph…
The climate graph below is for Paris. It is in the standard format that you would expect to see in an exam, scientific paper or perhaps on a travel website. The rainfall that falls each month is measured by the blue bars in millimetres. The average temperature for the month is detailed by the red line graph.
For example, it is clear that in August, 60mm of rain fell in Paris, in this specific year. This value is read off of the left vertical axis. The average temperature for the month of August is 19.4°C. This is determined by looking at where the red line sits relative to the right vertical axis.
It is important that you do not mix up which axis you should read off! Remember to look at the title of each axis to confirm that you are measuring either precipitation or temperature.
What other information can you determine from a climate graph?
Well, let’s look at the example above again.
Over a 12-month period, it is obvious that Paris receives quite a lot of rainfall. The most rain fell in the months of May and December with approximately 70 mm falling in each month. We can also determine that the least amount of rain falls in February. Only around 50 mm of rain falls this month.
The total rainfall for the entire year can be found by adding all of the values of the blue bars together. That means that within the period of time that the climate graph above is for, 670 mm of rain fell in Paris.
For temperature, we can make similar findings. We know that the hottest month is July with an average temperature of 19.8°C and the coldest month is January at 4.2°C. The average annual temperature is determined by adding the 12 data points and dividing them by 12. If the values were read with perfect accuracy, the average annual temperature in Paris was 11.6°C.
Interestingly, some climate graphs might be labelled ‘precipitation’ in which case snow, hail and sleet all fall into the category. This is unlucky to affect many countries, but it’s cool to see that higher winter precipitation totals for the likes of Spain could actually be snow.
Seasons
By looking at the large range in temperature and the shape of the gradient we can understand the seasons experienced in Paris. November, December, January and February clearly have significantly lower temperatures, proving that Paris would experience winter weather in this period. This is to be expected as it is the case for all cities at a similar distance from the equator. The UK for example would experience winter in these months also.
The climate graph clearly shows that Paris has summer weather between June and September – evidenced by the high temperatures. Between September and November, the temperature drops slightly and Paris is in autumn. Between March and June, temperatures rise and Paris experiences spring.
When will I ever need a climate graph?
Climate graphs are used for all sorts of things. If you’re a Geography student studying for your GCSE or A-Level exams then you are bound to come across a climate graph at some stage. Younger students may also cover climate graphs in their curriculum.
Even if you are not studying Geography, it is still useful to know how to read a climate graph.
If you’re planning a holiday but don’t like high temperatures, then a climate graph for a region is useful and you can tell which months you wouldn’t like to travel there. The data is also helpful in helping tourists with what to pack. Knowing if the area is likely to be dry and hot will change a decision to take a heavy, winter raincoat.
You’ll often find climate graphs on travel websites for this reason.
REMEMBER – a climate graph is evidence of a previously recorded year. While they give a good indication of what the weather is likely to be like, climate graphs are not an exact science. They can not predict exactly the amount of rain expected or the temperature within a month as storms, droughts and heatwaves could all impact the weather.
Conclusion
Climate graphs are quite easy to understand once you get the hang of them. They give information on the rainfall and average temperatures experienced within a region over a particular period of time.
Knowing how to read a climate graph is a useful skill to have. For students, it is expected but for others, it can help determine travelling. Climate graphs give a good indication of what the weather of a region will be like year to year but they should not be used as gospel as often weather patterns change annually.
