Wind generated Pressure inside buildings, normally referred to as “internal pressure” in engineering literature, has a profound effect on the atmospheric pressure measured with indoor barometers during severe storms. The magnitude of the internal pressure is proportional to the dynamic pressure (stagnation pressure) which in turn increases with the square of the wind speed. Normally, this pressure is negative, and it has a magnitude in the neighborhood of 50% of the stagnation pressure. Its value changes drastically when an opening such as a door or window is opened or broken in high winds. The internal pressure also fluctuates readily with the fluctuations of the external pressure when a large opening exists. Surface pressure measurements taken in severe storms may contain serious errors if this internal pressure effect is not corrected. The paper summarizes latest research findings on internal pressure reported in the literature, and explores their implications to meteorology—especially to the study of severe storms such as hurricanes and tornadoes. Measures to correct or reduce the error generated by internal pressure are also discussed.