...How Hot Can It Get Inside a Closed Vehicle?...


Don’t leave children or pets in a car while you run an errand – even if it’s just going to be for a few minutes. Temperatures can reach dangerous levels in a matter of minutes.  Beat the Heat - Check the Backseat!

On a sunny day a few summers ago, our friends at the National Weather Service Forecast Office near Sullivan, Wisconsin performed an unofficial experiment to determine how quickly an automobile would heat up in directly sunlight.  This simplified experiment consisted of putting an electronic thermometer inside a closed automobile (dark blue in color with sun to the rear), and another electronic therometer placed outside of the vehicle to measure ambient temperature in the shade. The interior and exterior readings were compared at timed increments.

The interior of the car was cooled to 83 degrees by the vehicle air conditioner, the engine was turned off and the monitoring was started. After only fifteen minutes the automobile interior heated to a deadly 120 degrees.  Many unofficial experiments have been conducted that indicate inside temperatures can rise 35 to 45 degrees above outside temperatures!

Here are the results:

Time              Interior temperature     Outside temperature
CDT                      degrees F                        degrees F

1245 pm                      83                                    92
100 pm                      120                                    93
115 pm                      123                                    94
130 pm                      125                                    93
145 pm                      127                                    94
200 pm                      129                                    94
215 pm                      130                                    95
230 pm                      131                                    95
245 pm                      132                                    95
300 pm                      133                                    95
315 pm                      134                                    95
330 pm                      134                                    95

When hot temperatures occur it is important to not leave children or pets in parked vehicles, even for short periods of time, under any circumstances!

Heat kills.  In the past dozen years over 450 children have died from heat exhaustion after being left in or gaining access to unattended cars!

The following is a web site that is useful in highlighting the tragic consequences of leaving children unattended in cars during hot spells  http://ggweather.com/heat/index.htm

Many thanks to the National Weather Service Forecast Office near Sullivan, Wisconsin for the information regarding the experiment cited above.



Return to News Archive

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.