Summer Heat Danger in Vehicles

3 trucks in a row
Looking at what factors cause trucks to heat up faster in the sun.

This story aired in July of 2011….

The July sun is high in the sky and days are long. No wonder it’s a hot month. My summer weather interns and I embark on an experiment for truth. How hot does it get in vehicles. How fast? and does the color matter? We did this on a day when the temperature outside News 5 was near 90.

I secured two white SUVs and a black one and played valet. I parked them facing the sun and put a sun shield in one of the white trucks. We left the windows open at first to get all the trucks to the same temperature. That was 100 degrees. The trucks were parked in the shade before we started. I closed the windows except for one of the back windows on each which I left open about 2″ so we could take infra red readings of the back seat.

After 5 minutes the white truck with sun shield warmed 8 degrees while the black truck warmed 13 degrees. After 10 minutes the white SUV with sun shield was 114. The other white SUV was 119, And the black one was 124 degrees.

Every 5 minutes Jessica Townsend and Jessica Chism took readings. I supplied the water!

After 30 minutes here’s what we found- The back seat of the white truck with sun shield was 121 degrees, the other white truck’s back seat was 125 degrees but the black truck’s back seat was 135 degrees.

All of those were shaded from the sun so we did one last measurement of the front seats. The front seat on the white car was also shaded by the sun shield so it was actually only 120.

The sunny front seat of the other white SUV was up to 151 degrees, and the sunny front seat of the black SUV was 153 degrees.

In direct sun the vehicle exterior color didn’t make much of a difference there since all the interiors were the same color.

roadway mirage
The distant puddle in the road on a hot day is often not water, it’s a mirage.

Now, what about the ground temperature? That had something to do with it. Jessica Chism found a 50 degree temperature difference in an area no more than 100 square feet based on what covered the ground. Dark asphalt in the sun was hottest at 135 degrees. Concrete in the sun was 124 degrees. Concrete in the shade was more reasonable at 94 degrees while grass in the sun was hotter at 104 degrees. The coolest area was grass in the shade at 85 degrees.

Our numbers may not be totally accurate in this simple experiment but it does give you some idea of where the real summer heat hangs out.

Darker vehicle warmed faster and farther while darker surfaces get much hotter in the sun than anything in the shade, especially grass and soil. We didn’t test window tinting or different color vehicle interiors but that will be a project for another day.

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