Winds are often used to measure intensity as they commonly cause notable impacts over large areas, and most popular tropical cyclone scales are organized around sustained wind speeds. However, variations in the averaging period of winds in different basins make inter-comparison difficult. In addition, other impacts like rainfall, storm surge, area of wind damage, and tornadoes can vary significantly in storms with similar wind speeds. Pressure is often used to compare tropical cyclones because the measurements are easier and use consistent methodology worldwide, in contrast to difficult-to-estimate maximum sustained winds whose measurement methods vary widely. Tropical cyclones can attain some of the lowest pressures over large areas on Earth. However, although there is a strong connection between lowered pressures and higher wind speeds, storms with the lowest pressures may not have the highest wind speeds, as each storm's relationship between wind and pressure is slightly different.
In the most recent and reliable records, most tropical cyclones which attained a pressure of 900 hPa (mbar) (26.56 inHg) or less have occurred in the Western North...