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Standard sea level pressure in millibars on surface charts

Remote Pilot (Part 107) practice question 19 of 19 on Weather / Sources. ACS element UA.III.A.K3 · difficulty: recall. Want to answer it in a timed quiz? Use the Remote Pilot (Part 107) practice mode.

Question bank updated 2026-09-22

QUESTIONSurface weather charts report pressure in millibars (mb). What is standard sea level pressure expressed in millibars?

  1. A1,040.0 mb
  2. B1,013.2 mb
  3. C950.0 mb, the lowest typical reading
Show the answer and explanation

Correct answer: B. 1,013.2 mb

  • A — incorrect 1,040.0 mb is the upper end of the range of typical millibar readings, not the standard value.
  • B — correct The study guide states that standard sea level pressure is 1,013.2 mb, the millibar equivalent of 29.92 "Hg.
  • C — incorrect 950.0 mb is correctly described as the low end of typical readings, but that is not standard sea level pressure.

BACKGROUND

The International Standard Atmosphere (ISA) gives aviation a common reference for performance data. Under ISA, standard sea level pressure is 29.92 inches of mercury ("Hg) with a standard temperature of 59 degrees Fahrenheit (15 degrees Celsius). Atmospheric pressure is also reported in millibars (mb), where 1 "Hg equals approximately 34 mb, making standard sea level pressure 1,013.2 mb. Typical millibar readings range from 950.0 to 1,040.0 mb. Surface charts, high and low pressure centers, and hurricane data are all reported using millibars, so a remote pilot reading those charts works in millibars rather than inches of mercury.

STUDY TIP

Memorize the two forms of standard sea level pressure together, 29.92 "Hg and 1,013.2 mb, and remember that surface charts and pressure centers use the millibar form. Keep the typical range of 950.0 to 1,040.0 mb in mind so you can tell a plausible reading from the standard value.

KEY POINTS

  • Standard sea level pressure is 29.92 "Hg, which equals 1,013.2 mb.
  • Surface charts, pressure centers and hurricane data are reported in millibars.
  • Typical millibar readings run from 950.0 to 1,040.0 mb; 1 "Hg is about 34 mb.

SOURCES

  • remote_pilot_study_guide.txt ch3b "Measurement of Atmosphere Pressure"
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SkyDrill is not affiliated with the FAA. This is an original practice item based on 14 CFR part 107, 14 CFR part 89, and the FAA Remote Pilot – Small UAS Study Guide (FAA-G-8082-22). Regulations and handbooks are revised; confirm details against the current edition.