Many years ago I watched a documentary covering different aspects about life in the high Arctic. Minutes were spent explaining how the arctic tundra was able to have such an explosion of blossoms from ground covering plants. The ground temperature was able to go much higher than in the open air, about 45 cm above.

I recently learned that for an official temperature reading, the thermometer and its location must meet specific criteria. It must be housed in a white painted louvered box at least .6 m x .6. x .6m The box must be on a post approximately 1.4 m. Above the ground and not influenced by unusual air currents eg a building ventilation outlet.

With our recent Hot Air Bubble in early July, I was curious about the temperature. I was wondering what it would be on the back of an insect caught out in a clear cut. The forecasters were talking about a range from 27°C –The “ground temperature” is real for some, not for the meteorologist or the general public.. In Lytton, the Canadian record temperature was recorded at 49.7°C

One day, which was slightly overcast I ventured into a clear cut. In direct sun, on the ground the temperature went to 41°C.   In the shade, minutes later the temperature was 25°C for a difference of about 16°C.

The next day, no clouds I went to a nearby clear-cut to repeat the experiment. In the shade of the forest the reading settled at 25°C. I moved the thermometer out into the clear cut, placed it on the ground, pointing directly into sun. The temperature at around 3:00 p.m. went above the scale. My estimate is 62 °C – at least double the shade temperature.

 The difference from the air measurement can somewhat explain how sidewalks have buckled in the heat of day. Others have cooked eggs on the surface of their dark coloured vehicles. No wonder dogs don’t like walking on concrete or pavement – it does slow cook their feet!

The “ground temperature” is real for some, not for the meteorologist or the general public. I wonder why they give a humidex ” Feels LIKE”  but not a ground temperature warning!!

Top photo credit: 25°C on the temperature gage hanging from a branch in the forest – photo by Rod Burns

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