What is the correct code for a 6-hourly maximum temperature of 21.0° Celsius?

The correct code for a 6-hourly maximum temperature of 21.0° Celsius is represented as 11020. This coding convention follows a specific format where the first two digits indicate the temperature in tenths of degrees Celsius, the next digit signifies the maximum or minimum temperature, and the last digit reflects the number of hours of the observation within a 6-hour period.

In this case, 21.0° Celsius converts to 210 tenths (since 21.0° equals 210 when expressed in tenths). The first digit, which is ‘1’, denotes that this is a maximum temperature observation. The next two digits, '20', indicate the actual maximum temperature recorded (again, expressed in tenths). Hence, this results in the code being structured as 11020, accurately describing a maximum temperature of 21.0° Celsius.

Understanding these conventions allows for proper interpretation and communication of temperature data in aviation weather reports.