Part 107, explained › Weather · Last reviewed October 25, 2026 against the eCFR and faa.gov. UAV Campus is not affiliated with the FAA.
What happens when a cold front or warm front passes?
A front is the boundary between two air masses, and temperature, humidity and wind often change rapidly across it. At a cold front, showers or thunderstorms, gusty variable winds and a sharp drop in temperature and dewpoint are typical. At a warm front, stratiform cloud, drizzle and poor visibility give way to steadily rising temperature.
Cold fronts move faster than warm fronts, typically 25 to 30 mph against 10 to 25 mph for a warm front. A cold front has a steep slope, so warm air is forced up abruptly, often giving a narrow band of showers and thunderstorms along or just ahead of the front. During passage the visibility is poor with winds variable and gusty, and the temperature and dewpoint drop rapidly. Barometric pressure falls quickly, bottoms out at passage, then rises.
A warm front has a gentle slope, which favors widespread layered cloud and precipitation along and ahead of the front if the rising air is stable. During passage, stratiform clouds are visible, drizzle may be falling, visibility is generally poor, and the temperature rises steadily. Wind shifts happen within any front, and the shift is most pronounced with cold fronts.
Sources: FAA-H-8083-28B, p. 137 · FAA-H-8083-28B, p. 138 · FAA-H-8083-28B, p. 139 · FAA-H-8083-25C (PHAK), p. 305 · Remote Pilot Study Guide, p. 34
What the FAA says
FAA-H-8083-28B, p. 137
A front is a boundary or transition zone between two air masses.
FAA-H-8083-28B, p. 139
During cold front passage, the visibility is poor with winds variable and gusty, and the temperature and dewpoint drop rapidly.
FAA-H-8083-28B, p. 138
During the passage of a warm front, stratiform clouds are visible, and drizzle may be falling. The visibility is generally poor but improves with variable winds. The temperature rises steadily from the inflow of relatively warmer air.
FAA-H-8083-25C (PHAK), p. 305
wind shifts are continually occurring within a front. Shifting wind direction is most pronounced in conjunction with cold fronts.
Sources: FAA-H-8083-28B, p. 137 · FAA-H-8083-28B, p. 139 · FAA-H-8083-28B, p. 138 · FAA-H-8083-25C (PHAK), p. 305
Exam traps
- A front is the boundary between two different air masses, and across it temperature, humidity and wind often change rapidly over short distances.
- Wind shifts occur within every front, and the shift is most pronounced with cold fronts.
- Cold fronts move faster than warm fronts and have a steep slope, so the weather is concentrated in a narrow band.
- A warm front brings stratiform cloud and drizzle with steadily rising temperature, while a cold front brings a rapid drop in temperature and dewpoint.
Quick quiz: 3 questions
Similar to the FAA test, not the actual test questions. Each answer shows its FAA source.
Question 1 of 3
One of the most easily recognized discontinuities across a front is
- A an increase in relative humidity.
- B a change in temperature.
- C an increase in cloud coverage.
Show the answer
Answer: B. a change in temperature.Because the two air masses that are colliding have different temperatures and different characteristics, they also tend to have different wind directions, so crossing a front will almost always lead to a change in wind direction and a change in temperature.
FAA source: FAA-G-8082-22 ch. 3b, Fronts
Question 2 of 3
One weather phenomenon which will always occur when flying across a front is a change in the
- A type of precipitation.
- B wind direction.
- C stability of the air mass.
Show the answer
Answer: B. wind direction.Because the two air masses that are colliding have different temperatures and different characteristics, they also tend to have different wind directions, so crossing a front will almost always lead to a change in wind direction and a change in temperature.
FAA source: FAA-H-8083-25C ch. 12, Wind Shifts
Question 3 of 3
The boundary between two different air masses is referred to as a
- A frontolysis.
- B frontogenesis.
- C front.
Show the answer
What happens to pressure when a cold front passes?
A quickly falling barometric pressure bottoms out during frontal passage and then begins a gradual increase. Falling pressure and a high dewpoint indicate an approaching cold front.
Source: FAA-H-8083-28B, p. 139
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More on this topic: Part 107 weather, task by task.