Mist (BR) in METAR visibility is defined as 5/8 mile up to six miles

How is mist (BR) defined in terms of visibility in a METAR?

• A. Less than 5/8 miles
• B. From 5/8 mile up to six miles
• C. From 1 mile up to 10 miles
• D. Any visibility beyond six miles

Answer: (B)

Mist (BR) is defined in meteorological terms as a weather phenomenon that typically causes visibility to decrease. In the context of METAR reports, mist is specifically characterized by a visibility range that falls between 5/8 mile up to six miles. This definition is crucial for pilots, meteorologists, and other aviation professionals as it helps them understand the conditions affecting visibility, which is vital for safe operations. When visibility is reduced to less than 5/8 mile, other weather phenomena such as fog would come into play, and thus mist is distinctly categorized to ensure clarity in communication regarding weather conditions. The range specified in the correct answer allows for a precise understanding of conditions that are less severe than fog but still noteworthy for weather observation and reporting.

Mist is one of those weather terms you only notice when it changes the way you see the world. In aviation, that moment—when the air gets a little milky and visibility slips—can shape a pilot’s decisions more than you’d think. If you’ve ever skimmed a METAR (the weather report pilots rely on), you’ve probably bumped into the five-letter code BR. What does BR stand for, and what does it tell you about visibility? Let’s unpack it, with a clear, practical angle you can actually use.

What BR means in a METAR

BR is the shorthand meteorologists use for mist. It’s not fog, and it’s not clear air. It occupies a special middle ground you’ll hear described as “somewhat hazy.” In the aviation world, the defining feature of mist is visibility that’s not great but not atrocious either. The official range for mist in METAR terms is 5/8 of a mile up to 6 miles. That 5/8 mile mark is just a hair over half a mile, and 6 miles is a comfortable sight line—enough to read runway signs from a distance, if the rest of the sky behaves.

To put it in numbers you can picture: BR means visibility is between approximately 0.625 miles (about 1 kilometer) and 6 miles. If you drop below 0.625 miles, the weather people call it fog, not mist. And if visibility is better than 6 miles, you’re outside the BR category altogether. Keeping that 5/8 to 6-mile window in mind is a quick way to translate a BR tag into real‑world sight lines.

Why that range matters for pilots and planners

Visibility isn’t just a number on a chart. It’s a compass for takeoffs, landings, and flight planning. Mist affects perception, horizon cues, and distance judgment in ways that aircraft systems can’t fully compensate for. When a METAR shows BR, pilots know they’re dealing with reduced visibility that’s not severe fog, but still enough to demand careful flying—especially during approach, runway selection, and taxiing.

A morning with BR can feel different from a clear morning even if you’re the kind of pilot who loves to “go, go, go.” You notice things you’d otherwise take for granted: the way lights appear through a milky veil, the way ground clutter fades in and out, or how quickly distance cues vanish as you bank toward a turn. Understanding BR helps you calibrate expectations and communicate more effectively with air traffic control and your crew. It’s not about anxiety; it’s about situational awareness and making conservative choices when visibility is tumbling inside that 0.625–6 mile corridor.

Differentiating mist from fog: two sides of the same weather coin

The difference between BR and fog (FG) isn’t just a number game. It’s a practical distinction with real flight implications. Fog is essentially a thicker blanket that reduces visibility to less than 0.625 miles in METAR terms. That might force the day’s plans to hinge on instrument flight rules (IFR) rather than visual cues, or even trigger delays or ground stops. Mist, by contrast, sits in that “there you can see enough to navigate, but not at a distance” zone. It’s enough to require extra caution, but not the same level of constraint as fog.

If you’ve ever found yourself thinking about “how bad is this really?” while looking out the window, you’re already instinctively comparing BR with FG. The METAR language formalizes that intuition. For students and professionals, knowing which category is in play helps you frame the risk and communicate it clearly in your weather briefings or internal notes.

Reading a METAR line with BR in it

Let’s translate a sample METAR snippet to make this concrete. Imagine you’re glancing at a METAR that reads something like:

METAR KAAA 091856Z 18012KT 2SM BR SCT020 BKN030 24/18 A2987

What does this tell you?

• 2SM BR: The prevailing visibility is 2 statute miles, and mist (BR) is the current weather phenomenon affecting that visibility. That’s clearly within the mist range (0.625 to 6 miles).

• SCT020 BKN030: The sky is partly obscured by scattered clouds at 2,000 feet and broken at 3,000 feet. The sky cover matters because it can limit what you see beyond the mist, adding another layer to your situational picture.

• 24/18: The temperature/dew point is 24/18. Not the star of the show here, but it helps you gauge how humid the air is and whether fog could become a future concern if conditions keep cooling.

• A2987: The altimeter setting. Terrain, airport elevation, and elevation corrections matter for approach and landing performance.

In real life, you’ll often see BR paired with other weather elements—wind, cloud cover, precipitation. The key takeaway is simple: when BR appears, your visibility is in that middle ground where you should expect hazy optics and adjust your procedures accordingly.

Practical takeaways for pilots, students, and observers

• Visual cues matter: BR makes distant landmarks harder to discern. If you’re flying VFR, you’ll probably want to keep your minimums within a conservative margin.

• Don’t rely on eye peering alone: in mist, depth perception can be tricky. Use instruments and rely on confirmatory cues from ATC and your flight deck teammates.

• Plan for variability: BR can fluctuate quickly as air moves and moisture pools or dissipates. A minute by minute forecast can tell you when to expect improvements or declines.

• Always cross-check: if the boundary between BR and FG is close in the forecast, verify the latest METARs and TAFs (terminal area forecast) to time maneuvering decisions more precisely.

• Know the local quirks: some airports have a history of BR appearing with certain wind patterns or humidity levels. A quick check of recent weather history at a field you frequent can save you a scramble.

Where to look for reliable BR information

If you want a steady stream of accurate weather intel, a few go-to resources are worth bookmarking:

• Aviation Weather Center (AWC) from NOAA: the official hub for METARs and the latest weather maps. It’s the go-to for pilots who want authoritative, up-to-date data.

• METAR-decoding tools and smartphone apps: many apps render METARs in human-friendly formats—great for quick checks between flight segments.

• Local weather briefings: for small airports, the on-record METARs and the METAR history can reveal patterns you’ll want to know before you head out.

• Flight planning software: mature packages pull METARs and TAFs into route planning, helping you visualize how BR could drift along your chosen path.

A few quick reminders as you build mental models

• BR always sits between 5/8 mile and 6 miles visibility. If you see numbers outside that, you’re likely looking at FG or something else in the weather vocabulary.

• BR is not a judgment about “how bad” the weather is by itself. It’s a descriptor of visibility in a specific range, and it works in concert with cloud cover, wind, and precipitation.

• The presence of BR can influence taxi, takeoff, and landing decisions. In the cockpit or on the ground, you’ll want to translate a BR reading into practical actions—like adjusting approach speeds, spacing, or margin for error.

A little analogy to keep the idea clear

Think of mist as a translucent curtain over the air. It’s thick enough to blur the stage lights and soften distant landmarks, but you can still see the foreground clearly enough to walk across the room with some caution. Fog, though, is more like a foggy window—everything beyond a few steps becomes a blur, and you’re forced to rely on instruments or wait for the curtain to lift. BR sits right in that “soft-focus” zone, telling you to stay mindful and prepared but not paralyzed.

Closing thoughts: BR is a small code with big implications

Mist in METAR isn’t a flashy meteorological headline. It’s a practical, everyday factor that pilots, meteorologists, and airfield operators weave into their decisions. By understanding that BR means 5/8 to 6 miles of visibility, you gain a clearer sense of what a pilot might experience on the ground, in the air, and on approach. It’s a tiny piece of a larger weather puzzle, but a piece that matters when your eyes and your instruments are guiding you home.

If you’re curious to see BR in action, pull up a recent METAR for a nearby field and look for the “BR” tag next to the visibility figure. Notice how the numbers align with your own impressions of the day. That kind of practice — looking at real reports and translating them into what you’d do in the cockpit — is what builds confident, capable weather literacy. And the more you absorb, the more natural it feels to read the sky like a story, not just a weather sheet.

In the end, BR isn’t just a line on a chart. It’s a practical cue about how far you can see, and what that means for safe, smooth flight operations. So the next time you run into BR in a METAR, take a moment to picture that faint curtain of mist and let it guide your next move. It’s a small detail, but it can make a big difference when you’re piloting through the morning haze.