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 today through 8 am tomorrow (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
1Montreal, Canada0.97 inHg8 am9 pm-0.075 inHg/hr
2Quebec, Canada0.94 inHg8 am9 pm-0.072 inHg/hr
3Halifax, Canada0.88 inHg8 am7 am tomorrow-0.038 inHg/hr
4Montpelier, Vermont0.8 inHg8 am11 pm-0.053 inHg/hr
5Philadelphia, Pennsylvania0.74 inHg8 am10 pm-0.053 inHg/hr
6Richmond, Virginia0.72 inHg8 am10 pm-0.051 inHg/hr
7New York, New York0.72 inHg8 am11 pm-0.048 inHg/hr
8Augusta, Maine0.72 inHg8 am4 am tomorrow-0.036 inHg/hr
9Sioux Falls, South Dakota0.68 inHg4 pm7 am tomorrow-0.045 inHg/hr
10Hartford, Connecticut0.67 inHg8 am12 am tomorrow-0.042 inHg/hr
11Boston, Massachusetts0.66 inHg8 am4 am tomorrow-0.033 inHg/hr
12New Haven, Connecticut0.65 inHg8 am12 am tomorrow-0.041 inHg/hr
13Worcester, Massachusetts0.65 inHg8 am4 am tomorrow-0.033 inHg/hr
14Providence, Rhode Island0.65 inHg8 am4 am tomorrow-0.033 inHg/hr
15Mexico City, Mexico0.63 inHg2 pm10 pm-0.079 inHg/hr
16Billings, Montana0.62 inHg8 am12 am tomorrow-0.039 inHg/hr
17Raleigh, North Carolina0.59 inHg8 am10 pm-0.042 inHg/hr
18Colorado Springs, Colorado0.55 inHg1 pm11 pm-0.055 inHg/hr
19Guadalajara, Mexico0.54 inHg3 pm11 pm-0.068 inHg/hr
20Rapid City, South Dakota0.53 inHg8 am6 am tomorrow-0.024 inHg/hr
= drop began before recorded 24-hour period (8 am today)
= drop continues beyond recorded 24-hour period (8 am tomorrow)

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.