Weather and Climate

When we start a day, usually we will be like today's weather is sunny or cloudy right? Similarly, we also say today's climate is too hot or cold. Most of us use weather and climate as synonymous, but have you ever thought of the difference, they have so that we can use the terms aptly?

After this read you can for sure use both the terms correctly. So firstly, we will see, what is weather?

Weather is the present state of the atmosphere around you (at a particular place and time). It varies from day to day.

The image given below shows different types of weather.

Suppose if we are starting to our workplace and the weather forecast given is rainy, then we will prefer car instead of a bike. So, depending upon the weather, we choose our transport.

Likewise, in the field of agriculture depending upon the weather, we decide the agricultural operations like sowing, irrigation, fertilizer application, pesticide application and so on.

Image source: Weather Blendspace by Karley Duncan

If the things that happens around us is weather, then what is climate?

Climate is the established pattern of weather over a region. In general, it is the average weather over a period of 30 years (as per WMO). The image below shows the World's climate (based on Koppen's climate classification).

Image Source: FAO - SDRN Agrometeorology group

Understanding Climate and Weather

For example, deserts are having dry climate (characterized by hot days and less rainfall) but the weather in the desert may be sunny or rainy on a particular day.

Now I hope that you understood the difference between weather and climate.

Apart from weather and climate other common words that we hear often these days from kids to elders and in multiple discussion forums, is "climate change".

So, let's get to know the basics of climate change.

For instance, if we feel too hot in the summer months of a year, then we generally say that it is because of climate change. But climate as we discussed earlier should not change every year, then what does this means?

This year to year fluctuation in temperature is climate variability, that occurs due to deviation from the normals (30 years average of temperature). It is the short term fluctuations around the average values.

Now you might be wondering then what is climate change?

The change that occurs over a decade or longer is climate change. For example: increase in global average surface temperature of 0.87ºC for the period 2006-2015 when compared to pre industrial time (1850-1900) (IPCC report) is climate change.

Understanding climate change and climate variability

If the difference from normals is for smaller timescales like months, seasons and years, then it is climate variability and if it's for longer timescales like decade or longer, then it is climate change. The following figure explains different time scales of weather, climate variability and climate change.

Image Source: Pacific-Australia Climate Change Science and Adaptation Planning Programme

How weather and climate influences agriculture?
	The Weather decides the crop production in a region and climate decides the suitability of a crop for a particular region.
For example: Let's take the apple crop
	Apples are mostly grown in temperate regions, due to their specific climatic requirement. It cannot be grown in all regions of the earth. This means,
Apple is suitable for temperate region is determined by climate and 
Apple production or yield in a particular year is determined by weather.