What Is Normal Barometric Pressure?
Normal barometric pressure at sea level is 1013.25 hPa — 29.92 inches of mercury — but that figure is a reference point, not a rule. Real-world readings wander from roughly 970 to 1050 hPa, and the atmosphere has strayed well past both edges.
This guide puts numbers on the whole question: where the 29.92 inHg standard comes from, the range actual weather delivers, the marks forecasters treat as high and low, how altitude rewrites the reading, and the record extremes ever measured at sea level.
Where normal sits on the scale
Chips mark the hPa values where normal (1009), high (1022), and the top of the everyday range (1050) begin. The records — 870 and 1084.8 hPa — live far off either end.
The standard-atmosphere answer: 1013.25 hPa
The official reference is the U.S. Standard Atmosphere of 1976, a NOAA/NASA/USAF model that fixes sea-level pressure at 1013.25 hPa — identically 29.92 inHg, or 760 mmHg. ICAO's International Standard Atmosphere uses the same figure, which is why every aircraft altimeter on the planet is calibrated against it.
The number is best read as the long-term, globe-averaged weight of the air column at elevation zero. A corrected reading near 1013.25 hPa says the atmosphere above you weighs about what it usually does — nothing more dramatic than that. Barometer dials print it at the center of the scale for exactly this reason.
What actual weather delivers: roughly 970–1050 hPa
Across ordinary weather, sea-level-corrected readings span about 970 to 1050 hPa. The bottom of that range belongs to deep winter storms and landfalling cyclones; the top belongs to cold, dense high-pressure domes that build over continents in winter.
Most days never approach either edge. A typical station spends its year within a couple dozen hPa of the standard, and a move of even 10 hPa in a day counts as an eventful barometer. The everyday range is wide on paper and narrow in practice — which is what makes the genuine excursions worth watching.
Where high and low begin
Working convention on this site and in most forecast copy: readings above about 1022 hPa (30.2 inHg) count as high pressure, and readings below about 1009 hPa (29.8 inHg) count as low. Between the two marks the barometer is simply unremarkable.
The labels are conventions, not physical constants — the atmosphere does not switch behavior at 1022 hPa. But they earn their keep because the weather associated with each side is real: sustained highs bring sinking air and quiet skies, sustained lows bring rising air, clouds, and precipitation.
Altitude rewrites the number
Pressure falls roughly 1 inHg per 1,000 ft of elevation near the surface — the NWS rule of thumb — so "normal" depends entirely on where the instrument sits. Denver, at about 5,280 ft, has a true station pressure near 24.6 inHg on a calm day, a value that would signal a historic storm at the coast.
That is why published readings are corrected to sea level before anyone compares them. The correction removes the elevation signal and leaves the weather signal, letting a mile-high metro and a coastal one share the same 29.92 inHg vocabulary. If your home barometer disagrees with the local airport, the elevation offset is almost always the reason.
The records: 870 to 1084.8 hPa
The highest sea-level pressure ever measured is 1084.8 hPa at Agata, Siberia, in December 1968 — a brutally cold Siberian high, since frigid air is dense air. The US record is close behind: 1078.6 hPa at Northway, Alaska, on January 31, 1989, set in an Alaskan cold dome.
The low end belongs to tropical cyclones. Typhoon Tip bottomed out at 870 hPa over the western Pacific in 1979 — the world record — and Hurricane Wilma set the Atlantic-basin mark at 882 hPa in 2005 (NOAA National Hurricane Center). For scale, Category 5 hurricanes typically deepen below about 920 hPa.
Season and latitude move the baseline
"Normal" also drifts with the calendar and the map. Winter favors both extremes at once: continental cold builds the strongest highs, while the storm tracks spin up the deepest lows, so mid-latitude and high-latitude stations swing hardest from November through March. Summer compresses the range nearly everywhere.
Geography sets the personality. Subtropical stations sit under semi-permanent highs and run slightly above standard for months; Honolulu's trade-wind barometer barely moves all year. High-latitude stations downstream of ocean storm factories — Anchorage under the Aleutian low is the US example — live with the widest swings on the map. The city pages below show both personalities.
Normal pressure, by the numbers
the sea-level standard atmosphere — the "normal" every scale anchors to
U.S. Standard Atmosphere 1976
the same standard in US weather-report units
U.S. Standard Atmosphere 1976
the lowest sea-level pressure ever measured — Typhoon Tip, 1979
NOAA NCEI / WMO
the highest ever measured — Agata, Siberia, 1968
NOAA NCEI / WMO
Check your local barometer
The most dramatic barometer traces in the US follow the storm tracks — the nor’easter lane up the East Coast and the Alberta-clipper lane across the northern plains — while trade-wind and Pacific-high metros barely move the needle. These pages show each city’s live pressure and trend, or look up any US city on the barometric pressure hub:
- Denver, CO barometric pressure — A mile up, its station pressure runs about 5 inHg below the sea-level standard on a completely ordinary day.
- Colorado Springs, CO barometric pressure — Higher still than Denver — the gap between the instrument reading and the reported value grows with every foot.
- Albuquerque, NM barometric pressure — Above 5,000 ft, another metro whose raw barometer reading would look like a monster storm at the coast.
- Salt Lake City, UT barometric pressure — Valley floor near 4,200 ft — reported pressure only makes sense after the sea-level correction.
- El Paso, TX barometric pressure — Desert elevation near 3,700 ft plus strong seasonal highs — a case study in reading corrected values.
- Honolulu, HI barometric pressure — The closest thing the US has to a textbook barometer: trade-wind readings that hug the standard atmosphere.
Frequently asked
- Is 30.10 inHg high barometric pressure?
- Slightly above the 29.92 inHg standard, but under the ~30.2 inHg (1022 hPa) mark where "high" conventionally begins. It reads as ordinary fair-weather pressure.
- What is considered low barometric pressure?
- Below about 1009 hPa (29.8 inHg) at sea level. Deep storms go far lower — the everyday floor sits near 970 hPa, and Typhoon Tip holds the world record at 870 hPa.
- Does normal barometric pressure change with altitude?
- Station pressure does — it falls roughly 1 inHg per 1,000 ft, which puts Denver near 24.6 inHg at the instrument. Published values are corrected to sea level, so the 29.92 inHg standard stays comparable everywhere.
- Are hPa and millibars the same unit?
- Yes — 1 hPa equals 1 mb by definition, so a 1016 mb chart and a 1016 hPa app agree exactly. The US-units equivalent divides by 33.8639: about 30.00 inHg in that example.
- What barometric pressure do hurricanes have?
- The deeper, the stronger. Category 5 storms typically run below about 920 hPa; Hurricane Wilma reached 882 hPa in 2005, the Atlantic record, and Typhoon Tip holds the world mark at 870 hPa.
- What is the highest barometric pressure ever recorded?
- 1084.8 hPa at Agata, Siberia, December 1968, inside an intensely cold Siberian high. The US record is 1078.6 hPa at Northway, Alaska on January 31, 1989.
- Is 29.92 inHg the average pressure everywhere?
- It's the sea-level standard, not a local average. Your local normal shifts with season, latitude, and regime — subtropical stations run a bit high, storm-track stations swing widely — but corrected readings from every city are expressed on the same 1013.25 hPa scale.