North Carolina · 100 m elevation

Barometric Pressure in Raleigh, NC

• 30.07Average pressure (inHg, sea level)
• 175.9Swing days a year · 27th of 50
• 84.2Big-swing days a year (≥10 hPa)
• 95.5Significant 24h drop days a year

Overview

Raleigh averages 30.07 inHg (1018.2 hPa) with 175.9 significant pressure swing days a year — 25.4 in January, just 2.8 in August. Records and trends.

Raleigh's barometer averages 30.07 inHg (1018.2 hPa) at sea level, with a median of 30.06 inHg (1017.9 hPa). Most of the year fits inside a fairly narrow band: the 5th percentile is 29.76 inHg (1007.8 hPa) and the 95th is 30.40 inHg (1029.6 hPa), with a standard deviation of 0.20 inHg (6.61 hPa). A typical 24-hour change is only 0.09 inHg (3.2 hPa).

At 100 meters of elevation, the correction between station pressure and sea-level pressure is small but visible. Mean surface pressure at Raleigh is 29.71 inHg (1006.2 hPa) — about 0.35 inHg (12 hPa) below the sea-level figure. An uncorrected home barometer will therefore read near 29.71 inHg on an ordinary day, not 30.07 inHg. That's an instrument offset, not a weather signal.

Nationally, Raleigh sits just below the middle of the pack on every routine measure: 175.9 significant swing days per year (national median 180.7, rank #27 of 50), 84.2 big-swing days (median 86.1, #26), and variability ranked #29. The exception is extremes. Raleigh's deepest 24-hour fall on record, 1.12 inHg (38 hPa), ranks #16 of 50 — essentially matching Denver's 1.16 inHg (39.2 hPa) despite Raleigh logging only 62% as many swing days as the country's most volatile city. Average conditions here are calm; the outliers are not.

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, Raleigh's defining feature is concentration rather than frequency. The city averages 175.9 days a year with a 24-hour change of at least 0.18 inHg (6 hPa), 84.2 days at or above 0.30 inHg (10 hPa), and 95.5 significant drop days. Those totals sit slightly below the national medians of 180.7 and 86.1. But 25.4 of the swing days land in January alone, versus 2.8 in August, and drop days follow the same shape: 14.0 in January against 1.2 in August. December through March accounts for the great majority of the conditions many pressure-sensitive people report as triggers.

Against other cities, Raleigh reads as moderately active. It logs 8.9 times Miami's 19.8 annual swing days, 1.52 times Atlanta's 115.6, and 1.89 times Atlanta's big-swing total of 44.5. Charlotte, three hours west, is a near peer at 158.8 — Raleigh runs about 1.11 times as many swing days. Denver, ranked #1 nationally, sees 281.6. So Raleigh falls well short of the country's most turbulent stations while remaining clearly more variable than the Deep South and coastal Florida.

The practical read: July through September is the quiet window, with all three months under 8 swing days each and August the calmest of the year. The demanding stretch is mid-December through March, when large single-day movements are most likely — the 95th-percentile 24-hour change reaches 0.38 inHg (12.7 hPa), and every one of the ten-year record's steepest falls occurred in that window. Anyone keeping a symptom log alongside barometer readings will find the most useful signal in those months.

Seasonal patterns

Raleigh effectively runs two pressure climates. From December through March it behaves like a storm-track city: January produces 25.4 significant swing days, February and March 23.2 each, December 22.4, and January's monthly standard deviation reaches 0.25 inHg (8.48 hPa). Mean pressure is also highest in this stretch — 30.13 inHg (1020.3 hPa) in January, 30.15 inHg (1021.1 hPa) in December — as strong surface highs alternate with passing mid-latitude storms and cold fronts crossing the Piedmont.

Summer is the opposite. August records just 2.8 swing days and July 3.2, with July's standard deviation falling to 0.10 inHg (3.49 hPa). January delivers roughly nine times August's count of swing days. June carries the year's lowest mean, 29.98 inHg (1015.2 hPa), and July 30.00 inHg (1015.9 hPa), but with very little day-to-day movement: the Bermuda high dominates and the pressure gradient flattens out for weeks at a time.

The extremes cluster tightly in the cold season. The record high, 30.86 inHg (1044.9 hPa), was set on January 9, 2017; the record low, 29.18 inHg (988.1 hPa), on February 7, 2020. All five of the sharpest 24-hour drops in the 2015-2024 record fall in December or January: -1.12 inHg (-38 hPa) ending January 9, 2024; -0.99 inHg (-33.4 hPa) on December 18, 2023; -0.87 inHg (-29.6 hPa) on January 17, 2022; -0.86 inHg (-29.1 hPa) on January 24, 2019; and -0.77 inHg (-26 hPa) on January 24, 2015. The fastest six-hour fall on record was -0.55 inHg (-18.6 hPa), and the largest 24-hour rise was +1.08 inHg (36.7 hPa).

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

• Charlotte, NC
• Virginia Beach, VA
• Washington, DC
• Baltimore, MD
• Philadelphia, PA
• Atlanta, GA

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