Open the sectional chart to the airport or airstrip your airplane is currently at. Look to the right upper hand corner of the airport icon to find the ATIS code. This is the radio frequency for the local ATIS broadcasts. Tune the radio into the ATIS frequency. For example, the ATIS clearance in Santa Barbara, CA is 132.65. Set the radio according to your charts ATIS code.
Listen to the updated ATIS reports and get wind, temperature and barometric readings, given numerically (such as 30.08.)
Turn the barometer dial to the ATIS barometric reading for the day. Listen for a NATO phonetic alphabet letter following the barometric broadcast. For example, "current barometer 30.08 with Alpha." This means the current barometer is 30.08 and when you call in to clearance you need to repeat the barometric number and tell them "with Alpha." This tells the clearance controller you have the most current barometric reading and your altimeter is set accordingly.
Request "flight following" during your scheduled flight. As you move through the flight, you receive updated barometric readings from the towers you pass over. Adjust the settings as your progress to remain accurate with the altimeter.
