Denver's 9,000-foot wind and temperature aloft are 230 true at 21 knots with -4 C

What is the wind and temperature aloft forecast for Denver at 9,000 ft?

• A. 230 true at 15 kts, temp -2 C
• B. 240 true at 19 kts, temp -5 C
• C. 230 true at 21 kts, temp -4 C
• D. 220 true at 25 kts, temp -3 C

Answer: (C)

The wind and temperature aloft forecast for Denver at 9,000 ft indicates specific atmospheric conditions that are essential for understanding weather patterns in that area. The correct choice states that the wind is from 230 degrees true at 21 knots and the temperature is -4 degrees Celsius. This answer is accurate because it reflects the typical wind patterns and temperature profiles that can occur at that altitude. The reported wind direction of 230 degrees true suggests a moderate westerly to southwesterly wind flow, which is common in many regions, especially in the foothills and plains surrounding Denver. The wind speed of 21 knots indicates a relatively strong breeze, which can influence flight conditions, weather systems, and turbulence. The temperature of -4 degrees Celsius is also plausible for 9,000 ft in Denver, particularly during the colder months or at higher elevations where temperatures are lower than at ground level. This temperature profile contributes to predicting conditions such as possible icing for aircraft or changes in weather patterns. Combining these elements—wind direction, speed, and temperature—provides essential data for pilots, meteorologists, and anyone needing to understand or navigate the atmospheric conditions in the Denver area at that altitude.

Denver’s weather pattern at altitude is a bit like listening to a seasoned guitarist: it has a consistent vibe, but the notes can surprise you if you don’t pay attention to the details. When you’re reading wind and temperature aloft forecasts, those details—the direction, the speed, the temperature—are the notes that tell you what the wind is doing up there and how the air will feel in the cabin or on an approach. Let’s walk through a specific example for Denver at 9,000 feet and decode what the numbers actually mean for pilots, planners, or anyone curious about how weather behaves up high.

What the forecast looks like, in plain terms

If you’ve seen the wind and temperature aloft forecast for Denver at 9,000 feet, you’ll come across four possible strings like these:

• A. 230 true at 15 kts, temp -2 C

• B. 240 true at 19 kts, temp -5 C

• C. 230 true at 21 kts, temp -4 C

• D. 220 true at 25 kts, temp -3 C

The correct choice is C: 230 true at 21 kts, temp -4 C. Now, let’s unpack what each piece means and why this one fits Denver’s atmosphere at that height.

Decoding the numbers: wind direction, speed, and temperature

• Wind direction “230 true”

• The 230 degrees is a compass bearing referencing true north (as opposed to magnetic north). So the wind is coming from the southwest, roughly aimed toward the northeast. You’ll hear pilots say “wind from 230” or “a 230 wind,” and they’re talking about where the wind originates, not where it’s blowing to.

• The “true” part matters more for aviation charts and forecast products that preserve a consistent frame of reference, especially when you’re comparing passes over large areas. In practice, most pilots are thinking about how the wind will push the airplane along its track, and the distinction between true vs magnetic is handled in the background by the navigation tools.

• Wind speed “21 kts”

• 21 knots is a brisk breeze for the altitude. It’s strong enough to noticeably affect an aircraft’s flight path, ground speed, and fuel planning, but not so strong as to be catastrophic. It’s the kind of wind that can cause mild to moderate crosswind components on certain approaches, depending on the aircraft’s own heading and course.

• Temperature “-4 C”

• At 9,000 feet, the air is cold. -4 C is just below freezing, which matters for things like ice formation and air density. In the cockpit, a colder air mass can affect engine performance and lift characteristics, and it also interacts with moisture to create the potential for icing if supercooled droplets are present. In short, the temperature helps determine what type of weather hazards you might encounter, even if you’re not flying through icing clouds.

Why this particular combination is plausible in Denver

Denver sits near the foothills of the Rockies, which means the wind there often has a strong west-to-southwesterly flavor, especially as air travels over the mountains and down into the plains. The 230-degree direction is a classic southwest wind at altitude in many seasons. The speed around 21 knots is energetic enough to be noticeable in a flight plan but not so intense as to dominate the entire weather picture. And the -4 C at 9,000 feet is right in the ballpark for a mid-winters’ day or a cooler spring day, given Denver’s elevation and typical diurnal temperature swings.

Why not the other options? A quick reality check

• A. 230 true at 15 kts, temp -2 C

• The direction is plausible, but the wind is a touch light here. If you’re looking for a stronger push at altitude—which matters for flight planning, turbulence potential, and route adjustments—15 kts is on the milder side. The combination would feel less dynamic than what you’d expect for a typical Denver crosswind at that height.

• B. 240 true at 19 kts, temp -5 C

• The direction is close, but the forecasted wind would be a bit more westerly-forward (toward 240) and the speed is still shy of the 21 kts mark. The temperature is a degree cooler, which affects icing risk and air density, but the overall feel isn’t the same balance you’d anticipate for this altitude in Denver.

• D. 220 true at 25 kts, temp -3 C

• This one cranks the wind speed up to 25 knots, which would be a fairly gusty profile for a routine leg or approach. A 220-degree wind means the air is coming from the southwest but at a slightly different angle, and a higher speed changes the crosswind components and turbulence potential. The -3 C is plausible, but the wind number doesn’t match the typical pattern you’d see at 9,000 feet in this region as cleanly as option C.

A practical read: what pilots actually do with this data

• Plan ground speed and course

• Wind at altitude doesn’t just push the airplane sideways; it shaves or adds to your ground speed depending on your track. If you’re flying a course that’s roughly northeast, a southwest wind from 230 degrees at 21 knots will slow you down a bit and push you off your intended track. Navigators and flight computers automatically compensate, but understanding the math helps you stay situationally aware.

• Assess fuel and timing

• A stronger wind aloft can shorten or lengthen flight times. If you’re counting on a certain leg length, that 21-knot wind might shave a few minutes off or add a few minutes to the route, depending on direction. That translates into fuel planning, reserve margins, and often a quick re-check of alternate options.

• Consider icing and performance

• Temperature at altitude influences the icing threat. At -4 C, icing isn’t guaranteed, but it is possible if there’s visible moisture in subfreezing air. Pilots keep an eye on ice potential and adjust speeds, engine settings, and altitude if conditions warrant it. Cold air can also affect engine efficiency and aerodynamic performance, which means you might notice the need for a slightly different climb or descent profile.

• Turbulence and light shear

• Winds aloft aren’t always a straight line. There can be shear, squalls, or convective pockets that show up as turbulence. A 21-knot wind from 230 degrees is a neat, well-behaved forecast most days, but a quick weather check before a leg helps you anticipate any bumps or deviations.

Denver-specific mindset: how terrain swirls into the forecast

The Rockies aren’t just a backdrop; they actively shape wind patterns. When air flows over high terrain, you get mountain waves, lee gusts, and sometimes upslope flow on the windward side. At 9,000 feet, you’re high enough to be influenced by these features, but still low enough that the air mass might carry moisture from lower levels. That combination can set up neat, sometimes tricky, weather situations. The forecast of 230 true at 21 kts with -4 C reflects a balance you might expect in a cool, clear, or partly cloudy day over the plains with the mountains nearby.

A simple mental model to read winds aloft

Here’s a quick way to visualize what that forecast is saying:

• Imagine the wind as a moving hand coming from the southwest. It’s not pushing straight down your flight path; it’s pushing at an angle, nudging your track and speed.

• The speed (21 kts) is enough to notice the shift in ground speed, but not so strong that you’re fighting a gale. It’s a steady breeze you plan for.

• The temperature (-4 C) tells you there’s a cool air mass up there. If there’s moisture, ice is possible; if not, you’ll mainly notice density altitude effects and engine performance differences.

Where to look for the data and how to use it in real life

• Primary sources

• Aviation Weather Center, NOAA’s official aviation weather product, publishes wind and temperature aloft forecasts for many altitudes, including 9,000 feet. You’ll see wind direction in degrees true, wind speed in knots, and the temperature in Celsius. This is the standard reference that pilots and aviation professionals rely on for planning and in-flight decision-making.

• How it’s presented

• The numbers are concise, but the implications aren’t hidden. Direction tells you where the air is coming from; speed tells you how hard it’s pushing; temperature gives you a hint about air density, possible icing, and engine/airframe considerations.

• Practical checks

• Cross-check with local METARs and area forecasts for a fuller picture. If you’re in a mountainous region, give a nod to terrain-induced patterns. If you’re in a cold season, keep a mental note about how colder air at altitude interacts with moisture and flight levels.

A few tips to remember for aloft forecasts

• Don’t ignore the reference frame

• True wind direction can differ from magnetic direction, especially when you’re talking about larger scale weather. The forecast will use true direction, and your navigation system will account for magnetic variation as needed.

• Use the numbers as a bundle

• Don’t just memorize the direction or the speed in isolation. The combination of 230 degrees and 21 knots at -4 C is a snapshot of what the air mass is doing. Together they shape the flight path, the climb/descent profile, and possible weather hazards.

• Think through the implications

• Consider how the wind would affect a leg you’re planning. Are you trying to fly along a certain track? Is the wind pushing you off course? What about icing risk? These questions help turn raw numbers into actionable planning.

In the end, the forecast for Denver at 9,000 feet—230 true at 21 kts with a temperature of -4 C—offers a compact portrait of the air you’ll encounter up there. It’s a reminder that altitude isn’t just a number on a chart. It’s a dynamic layer of the atmosphere that interacts with terrain, moisture, and time to shape how a flight feels, how long it takes, and what hazards might be waiting in the clouds.

If you’re exploring the broader world of FAI weather scenarios, you’ll notice how these aloft readings connect to the bigger picture: planning routes, anticipating weather transitions, and understanding why a seemingly calm horizon can suddenly invite a breeze that nudges you off your planned path. The more you get comfortable with reading these forecasts, the more you’ll feel like you’re reading the weather with a bit of home-court advantage.

And hey, the next time you glance at a winds aloft forecast, you’ll know exactly what the numbers are saying about Denver—the wind coming from the southwest at a steady 21 knots, with air that’s just cold enough to keep you on your toes. It’s a small set of numbers, really, but when you connect them to the ground below and the aircraft you’re flying, they become a practical compass for the sky.