When is it too hot to ride my horse?

As summer begins to wind down and the kids go back to school, it seems that no one bothered to tell Mother Nature. The only way to describe the oppressive heat and humidity we are currently experiencing is brutal. With a regular heat index of over 100°f (37.8°c), I often hear people asking is it too hot to ride. If you search online for the answer, you will come across a variety of advice and formulas. Some would allow you to ride just about year-round, and others would have you never riding between June - September. In this blog, I combined facts, science, and common sense and came up with a system that works for my horses and me.

Keeping Cool

The average temperature of an adult is between 97°f - 99°f (36°c - 37°c). The average temperature of a horse is 99°f - 101.5°f (37°c - 39c°). Horses and humans use the same two methods to keep cool.

• Sweating: Sweat glands release sweat, as it evaporates it cools the skin. This helps to lower your internal temperature.
• Vasodilatation: Blood vessels under your skin expand. This increases blood flow to your skin where it is cooler allowing your body to release heat through heat radiation.

These methods function well until the heat index exceeds the average body temperature. So, what is heat index sometimes referred to as real feel? 

What is Heat Index?

According to The National Oceanic and Atmospheric Administration (NOAA), the heat index is what the temperature feels like to the human body when relative humidity is combined with the air temperature. Unfortunately, calculating heat index isn't as easy as adding the temperature and humidity together as many people think.

The heat index formula is expressed as

HI= c₁+c₂T+c₃R+c₄TR+c₅T₂+c₆R₂+c₇T₂R+c₈TR₂+c₉T₂R₂

In this formula,
HI = heat index in degrees Fahrenheit
R = Relative humidity
T = Temperature in ∘F
c₁ = -42.379
c₂= -2.04901523
c₃ = -10.14333127
c₄ = -0.22475541
c₅ = -6.83783 x 10⁻³
c₆ = -5.481717 x 10⁻²
c₇ = -1.22874 x 10⁻³
c₈ = 8.5282 x 10⁻⁴
c₉ = -1.99 x 10⁻⁶

Assuming any of the above formula makes sense ain't nobody got time for that!

How to Calculate Heat Index

NOAA has a calculator that you can use assuming you know the temperature and humidity. To find these easily, I recently bought a temperature and humidity gauge to keep at the barn. Going to the link is time-consuming so I prefer to use the graph, below, that was created by NOAA. I have it pinned on the wall under the temperature and humidity gauge. You also have the option of purchasing a gauge that indicated the severity of the heat index.

Common sense tells you that it will be slightly cooler in the morning and later evening so those are the best times to ride. Unfortunately, not everyone has that as an option. Hopefully, the above information will make it easier for you to decide if it is safe to ride.

NOTE: I am not a veterinarian or doctor. The views expressed in this blog are my own and should not be taken as medical facts. If you are concerned about working/riding outside in the summer, consult a doctor or veterinarian.

Your one-stop shop for all things equestrian.

Follow our every move and keep up-to-date with tips, advice, and events, etc.