A scar could be affected by changes in air pressure, humidity and temperature. Yes your scar could be sensitive to weather patterns.
Changes to the nerves or if the nerves have not fully repaired may make them sensitive to changes in pressure. In cold weather blood vessels can constrict, this could affect blood flow to your scar area. Also think about how your skin generally feels more dry in winter, this is going to be the same for your scar. You might notice your scar feels tighter, the area may feel more stiff and restricted. If you need to moisturise your lips, you probably need to moisturise your scar! If your neck is cold, your scar might also be cold. Low humidity, a dryer atmosphere can lead to scar tissue feeling tight and itchy. In humid conditions if you are sweating you might find that if your scar is particularly sensitive it can also lead to irritation and itching. Keeping the area clean and dry might help in this instance.
You might notice some of your scar symptoms are more noticeable with weather changes, such as before a thunder storm. For some it could be during an airplane flight. Things like itching, scar pain and even swelling can be more marked. Think of those swollen ankles during a flight. Pressure changes affect circulation, so you have less blood flow and then as the tissue expands it can put more pressure on the scar.
You might find that using specialist silicon products could help. Moisturising your scar before your flight and even a gentle self massage could keep things hydrated and promote better circulation which might lesson or fully alleviate the symptoms. If you are at home a heat pad might help. Breathing exercises can often help. A few minutes of focused and mindful breath work can induce a calming affect and help you to relax. Also visualise what is happening to the organs and tissue inside, think of a few moments of deep breathing as an internal massage. For more severe symptoms pain medication and creams containing numbing agents.
Extra reading and geek time on weather and pain –https://doi.org/10.1016/j.brainresbull.2023.110696
Diagnoisis, Treatment, and Management of Painful Scar: A Narrative Review interesting – doi: 10.2147/JPR.S355096
This article from 2022 can give you an insight as to how m=painful scars develop and different treatment options and the evidence for use.