Cities with Greatest Drop in Barometric Pressure


The following cities are experiencing the biggest drops in barometric pressure today among our tracked cities. This is determined by finding the widest range between the highest and lowest pressures during the 24-hour period starting and ending at midnight, UTC−08:00 (Pacific Standard Time) in each city and filtering for the cities where the time of the highest pressure precedes the time of the lowest pressure.

Because each reading represents a 24-hour window of an hourly weather forecast, from 8 am yesterday through 8 am today (local time), it is possible that the full range of the falling pressure pattern is not captured in the data. In this case, the green triangle () indicates that the highest pressure observed during this period was at the start, meaning that the pressure had likely fallen from a higher high. Conversely, the red inverted triangle () indicates that the lowest pressure forecasted during this period is at the end, meaning that the pressure will likely continue to fall beyond the lower end of the range observed. Therefore, red and/or green triangles indicate that the total drop is likely to be greater than the amount displayed.


#CityDecreaseHigh TimeLow TimeRate
1Mexico City, Mexico0.58 inHg2 pm yesterday11 pm yesterday-0.064 inHg/hr
2Edmonton, Canada0.57 inHg8 am yesterday7 am-0.025 inHg/hr
3Guadalajara, Mexico0.51 inHg2 pm yesterday11 pm yesterday-0.057 inHg/hr
4Calgary, Canada0.49 inHg8 am yesterday7 am-0.021 inHg/hr
5Ottawa, Canada0.46 inHg8 am yesterday7 am-0.020 inHg/hr
6Bogota, Colombia0.44 inHg1 pm yesterday8 pm yesterday-0.063 inHg/hr
7Montreal, Canada0.43 inHg12 pm yesterday7 am-0.023 inHg/hr
8Djalo, Democratic Republic of the Congo0.42 inHg8 am yesterday2 pm yesterday-0.070 inHg/hr
9Quebec, Canada0.42 inHg1 pm yesterday7 am-0.023 inHg/hr
10Montpelier, Vermont0.4 inHg11 am yesterday7 am-0.020 inHg/hr
11Ulaanbaatar, Mongolia0.38 inHg4 pm yesterday7 am-0.025 inHg/hr
12Monterrey, Mexico0.37 inHg4 pm yesterday11 pm yesterday-0.053 inHg/hr
13Madrid, Spain0.36 inHg8 am yesterday4 am-0.018 inHg/hr
14Rochester, New York0.36 inHg8 am yesterday7 am-0.016 inHg/hr
15Augusta, Maine0.36 inHg1 pm yesterday7 am-0.020 inHg/hr
16Toronto, Canada0.36 inHg8 am yesterday7 am-0.016 inHg/hr
17Caracas, Venezuela0.35 inHg2 pm yesterday8 pm yesterday-0.058 inHg/hr
18Missoula, Montana0.34 inHg3 pm yesterday2 am-0.031 inHg/hr
19Saskatoon, Canada0.34 inHg3 pm yesterday7 am-0.021 inHg/hr
20Dar es Salaam, Tanzania0.34 inHg8 am yesterday1 pm yesterday-0.068 inHg/hr
Legend:
= drop began before recorded 24-hour period (8 am yesterday)
= drop continues beyond recorded 24-hour period (8 am today)




The change and rate of change in barometric pressure is often seen as being more important than the actual pressure value. That is why on many digital barometric pressure displays, the pressure readings are accompanied by “rising” or “falling” indicators. In meteorology, falling pressure is usually a sign of worsening weather, such as an incoming storm, increasing winds, more clouds, or more precipitation.

To folks who experience migraines, joint pain, or other physical conditions that are sensitive to pressure changes, falling pressure typically feels worse than rising pressure, though changes in pressure affect people differently, and stable pressure is generally preferred to larger or more rapid changes in pressure.