When are METARs issued?

METARs, which stand for Meteorological Aerodrome Report, are scheduled observations of weather conditions at an airport or aerodrome. They are typically issued every hour, but the key feature is that they are reported at the hour and 55 minutes past the hour. This means that a METAR would be generated at 01:00, 02:00, and also at 01:55, 02:55, etc. This practice ensures that pilots and air traffic controllers receive the latest weather information just before the start of the new hour, allowing for timely and relevant weather data.

The frequency of issuance provides a reliable update on the weather conditions that may affect flight operations, ensuring safety in aviation. While the other options mention different timings or conditions that don't align with the standard issuance schedule for METARs, the 55-minute mark effectively allows for actual observation times to be consolidated just before the new hour, thus providing more accurate and timely information to the aviation community.