In case you didn’t notice, it’s HOT outside. This is hardly surprising considering the calendar is set at “July going on August”, which some people call “the dog days”. If you have an air conditioner, it’s probably hard at work and if you don’t have one… well, you’re probably wishing for it. This is a great time to talk about an index, but not the financial indices we usually discuss such as the Big Mac Index or the Misery Index. Nope, today we want to discuss ‘the heat index’. Fitting, right?

The heat index (with the adorable nickname ‘humidex’) combines air temperature and relative humidity in the shade. Its aim is to determine how human perception of a specific temperature, or, simply put: How hot it feel while considering humidity. Want an example? You got it: When the temperature is 32 °C with about 70% relative humidity, the heat index shows 41 °C. This can also be looked at backwards: A heat index temperature of 32 °C can be viewed as having a relative humidity of 38%. The experts that did the calculation inform us that 15% of extra moisture can raise the heat index 13 degrees, causing 38 °C degrees to feel like 51 °C degrees.

This index has been around for a while. It was developed back in 1978 by a guy named George Winterling, and the USA’s National Weather Service was quick to adopt it only a year later. There are many factors that can impact the heat index, but only few people are aware to the fact that corn – yes, the sweet kind that comes on the cob – is one of them. Well, mainly in the United States.

Did you know corn actually sweats? It does and usually that’s not such a big deal. Like most plants, corn extracts water vapor when it “inhales” carbon dioxide. According to the United States Department of Agriculture, there are over 90 million acres of corn in the country’s Corn Belt. Now, we’re not exactly sure what an acre is, but it sure sounds like a lot of corn, which means, of course, a lot of corn sweat that turns into humidity.

In fact, one acre of corn can release as much as 4,000 gallons (that’s 15,141 liters) of water into the air on a single summer day.

Is corn the sole responsible for how hot it feels in certain areas of the world? Of course not. The calendar shows July and August and we bet that even in 2500 BC, before corn spread across the Americas, people were still complaining about the July heat. However, corn can certainly be an intensifying factor, and even a few degrees, even perceived degrees, can make a big change during summer.

At iFOREX you can invest in the price of corn, and many other agriculture commodities such as cocoa, coffee and sugar, and you don’t; even need to actually buy them and store them in your house. Want to learn how it’s done? Visit our education center and schedule a 1-on-1 session with a trading coach.