In a METAR, what does the 'T' group signify?

The 'T' group in a METAR report specifically denotes the temperature readings that are taken at the moment the report is issued, rather than at predetermined times like noon. It provides precise temperature values along with their respective dew point readings, which are vital for pilots and meteorologists to evaluate current weather conditions. This format offers a clear understanding of the atmospheric temperature, which can aid in decision-making processes related to flight operations, such as assessing potential icing conditions or adjusting performance calculations for aircraft.

While other options mention aspects of temperature or weather, they do not accurately capture the exact purpose of the 'T' group in METARs, which is focused on providing immediate and specific temperature data at the time of reporting.