Texas · 140 m elevation

Barometric Pressure in Dallas, TX

• 30.01Average pressure (inHg, sea level)
• 155.1Swing days a year · 30th of 50
• 70.2Big-swing days a year (≥10 hPa)
• 84.0Significant 24h drop days a year

Overview

Dallas averages 30.01 inHg (1016.4 hPa). January brings 24.6 significant pressure swing days; July averages 0.3. Records, monthly data, 2015-2024 trends.

Dallas sits at 140 meters above sea level and averages 30.01 inHg (1016.4 hPa) at sea-level equivalent across 2015-2024. The median reading is 29.99 inHg (1015.5 hPa), and the 5th-to-95th percentile range runs from 29.73 inHg (1006.9 hPa) to 30.37 inHg (1028.6 hPa). The standard deviation is 0.19 inHg (6.57 hPa), just under the 50-city median of 6.87 hPa.

Station pressure — what an uncalibrated barometer actually measures in Dallas — averages 29.53 inHg (999.9 hPa), about 0.49 inHg below the sea-level-adjusted numbers you hear on a forecast. If your home instrument reads near 29.5 inHg on an ordinary day, it is working correctly; it simply is not applying the altitude correction. Most consumer barometers let you offset by that amount.

Nationally, Dallas ranks #30 of 50 for significant swing days (155.1 per year against a national median of 180.7), #31 for big-swing days (70.2 versus a median of 86.1), and #30 for overall variability. Denver, the most volatile city in the set, records 1.82 times as many swing days and 2.42 times as many big-swing days. Miami, the calmest, records one-eighth of Dallas's total. Those middling ranks, though, average away the most important fact about pressure in North Texas: the annual figure blends two climates that barely resemble each other.

Migraine & pressure-sensitivity outlook

• Low — under 6 hPa (0.18 inHg)
• Elevated — 6 to 10 hPa
• High — 10 hPa (0.30 inHg) or more
• Dashed outline = forecast (after today)

Association only. This calendar shows days when pressure changed — or is forecast to change — sharply over 24 hours, conditions associated with pressure sensitivity in some people. It is not a prediction of symptoms, not a diagnosis, and not medical advice. The 30 days of history are there so you can compare the days you actually felt something against what the barometer did. Talk to a clinician about headache or migraine management.

For people who track barometric pressure as a symptom trigger, Dallas is a seasonal city rather than a consistently difficult one. It averages 155.1 significant swing days and 84.0 drop days — significant 24-hour falls — per year, both below national medians. Big-swing days of 0.30 inHg (10 hPa) or more occur 70.2 times a year. The typical 24-hour change is only 0.08 inHg (2.6 hPa), but the 95th percentile reaches 0.35 inHg (11.9 hPa), the kind of rapid change many pressure-sensitive people report as a trigger.

Those annual figures should be read month by month. January (14.4 drop days), February (13.7), December (12.1), and March (12.0) each concentrate more falling-pressure days than the entire June-through-September stretch combined, which totals about 2.4. July averages zero drop days over the ten-year period. If your pattern is tied to falling pressure, the active window in Dallas runs roughly from late November through March, and the summer is genuinely quiet — quieter, month for month, than most of the year in cities usually described as calm.

Compared with peers: Dallas sees 1.45 times as many swing days as Houston, 7.8 times as many as Miami, and about 5 percent fewer than Fort Worth, 30 miles west at 163.0. Texas volatility grades downward from north to south — Austin at 132.0 and San Antonio at 125.9 sit below both Metroplex cities. Against Denver's 281.6 swing days and 0.50 inHg (17.0 hPa) 95th-percentile change, Dallas is a comparatively stable place, with its instability packed into five winter months rather than spread across the calendar.

Seasonal patterns

The split is stark. January delivers 24.6 significant swing days — 24-hour changes of 0.18 inHg (6 hPa) or more — with a monthly standard deviation of 0.25 inHg (8.38 hPa) and a mean of 30.16 inHg (1021.2 hPa). July delivers 0.3 swing days, with a standard deviation of 0.08 inHg (2.68 hPa). February (22.4 swing days), December (21.0), March (20.9), and November (19.7) all run close to January. June, August, and September together contribute fewer than seven swing days a year.

The mechanism is straightforward. From November through March the polar jet steers cold fronts across the southern Plains, and nothing between the Rockies and the Gulf slows them down; each frontal passage produces a pressure fall and a sharp recovery behind it. From June through September the subtropical ridge settles over Texas, the horizontal pressure gradient collapses, and the barometer flattens out. Monthly means track the same cycle, falling from 30.16 inHg (1021.2 hPa) in January to 29.91 inHg (1012.9 hPa) in June.

Every one of the five sharpest 24-hour drops on record fell between late November and early March. The largest, 0.63 inHg (21.5 hPa), ended on February 26, 2023 — days before the ten-year low of 29.31 inHg (992.7 hPa) on March 2, 2023. Next come 0.63 inHg (21.3 hPa) ending November 28, 2016; 0.60 inHg (20.2 hPa) ending January 8, 2024; another 0.60 inHg (20.2 hPa) ending December 16, 2016; and 0.59 inHg (20.1 hPa) ending January 8, 2015. That last one is the cleanest illustration of the pattern: the ten-year high of 30.91 inHg (1046.7 hPa) was set at 9 p.m. on January 7, 2015, and the barometer gave back 0.59 inHg (20.1 hPa) over the following 24 hours. The largest recorded rise, 0.98 inHg (33.1 hPa), and the fastest six-hour fall, 0.32 inHg (11.0 hPa), also belong to the cold season.

Month by month

Swing days: 24-hour change of at least 6 hPa (0.18 inHg). Drop days: 24-hour fall of at least 6 hPa. Averages per year, 2015–2024.

Records and extremes

Sharpest 24-hour drops, 2015–2024

Nearby cities

• Fort Worth, TX
• Austin, TX
• Oklahoma City, OK
• Houston, TX
• Tulsa, OK
• San Antonio, TX

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