Calculate temperature change with elevation

It’s no secret that the temperatures high up in the mountains will be lower than that in the valleys. Have you ever set off on a warm summer hike to find the temps at the peak in the 50’s or worse?
Avoid these surprises by knowing how to calculate the temperature loss as you climb. Here are the steps involved, and a simple equation to reference.

 

  • Look up the weather forecast

Obviously, you need a base to go on. Look up the local area forecast, and see what the high, and low temperatures are going to be.

  • Determine the elevation of reference for the forecast.

All weather forecasts are referenced to a particular elevation. Using the National Weather Service website you can a detailed forecast, and they’ll list the elevation of reference on the page. If that information isn’t available, it’s usually the same elevation as your official city elevation. Here, we’re at 2,000 feet, and our forecast are all for 2,000 feet.

http://www.weather.gov/

  • Determine your peak elevation

Now you need to know how high up you are going to climb or descend. Reference your topo map, or find these details online. A quick Google with “Mountain (Name) elevation” will normally get you what you need.

  • Do the math

You will lose an average 3.5 degrees Fahrenheit for every 1000 feet of elevation you gain.

If you start out at 1000 feet, and climb to 6000 feet, that’s a 5000 foot difference (6000 – 1000 = 5000). So, since you’re gaining 5,000 degrees, you’ll use a 5 in your calculation. 5,000 feet, times 3.5 degrees. Just drop the (thousand). So, ( 5 x 3.5 =  17.5 degrees). So roughly, you’ll expect to lose at least 17.5 degrees. I always round up to the nearest 5 just to add some safety buffer, so a 20 degree difference. Simply subtract this number form your expected low, according to the forecast, and you have your expected temperature.

Ex: The weather man says it’s going to me 60 degrees today for the high in your city. Your city is at 6,000 foot. If you’re climbing from 6,000 feet to 14,000 feet, That’s an 8,000 foot difference. 8 times 3.5 is 28 (8 x 3.5 = 28). You can assume a 30 degree difference after rounding, so it’s only going to be 30 degrees max at the top of the mountain (A high of 60 minus your 30 difference)! Remember, that’s for the high. Always consider your low temperatures too.

Factors that affect your actual temperature

Some factors change the actual value of these calculations. Cloud cover will trap in more heat, where a clear sky will drop the temperature slightly faster. Cold fronts and air streams may also have an effect, as well as local evaporation cooling. These factors are too numerous to account for, so the equation is designed as a worst case scenario calculation (after rounding).

Equation  

( 3.5 x Change in elevation)/1000 = temp loss due to elevation change

or (3.5ΔH=Tf)

Thanks as always for reading! Don’t forget to follow our blog for future updates and reviews. It helps us out a lot. If you have any questions, comment below, send us an email, or find us on Twitter or Facebook (links on the right).

 

Advertisements

19 thoughts on “Calculate temperature change with elevation

    • The 3.5 is a little complicated, but basically the average combination of variables that affect the temperature, such as cloud cover, humidity, pressure, air density, and a few other factors. The 3.5 isn’t a perfect estimator, but it works pretty well in most conditions.

  1. This begins at 1000m correct? So moving from sea level to 1000m doesn’t apply to this formula. Can you explain why that is?

    • That’s true. It comes down to how the formula works. If you’re at sea level, the you’re multiplying by 0000 feet…so 0 temperature change. You’ll always get a zero. The formula just breaks down at anything below that. You could replace 500 feet of change with a .5, or something similar to that, but near ground level humidity and pressures throw off the assumptions built into the formula anyway.
      There is some fuzziness though. If you’re looking at a forecast, your forecast may be at 2000 feet (usually the elevation of the city) or 6000 feet. So if you plan to camp at 6000 feet, but your forecast is only for 2000 feet, you would only calculate in a 4000 foot change.

  2. on the same latitude the temperature at X is 25 degree Celsius what is the temperature at altitude 1000 metres above sea level

    • Assuming 1000 meters is above your starting point, you would loose about 10 degrees Fahrenheit (or about 1.6 celcius if my conversion is correct). Some fluctuation due to humidity and cloud cover.

  3. if i go up 1 km high , what is the temp variation on the 1st kilo meter’s end.
    or
    what is the temperature variance

  4. Pingback: How To Calculate Temperature Difference | Tiriya5

  5. Pingback: The top 5 Mistakes Beginner Backpackers Make | TreeLineBackpacker

  6. can you help to solve this qn
    temperature at zimbambwe village 950m is 24c.What will the temperature be at Zimbambwe town 5895m above the sea level

    • Hi there!
      Sure thing. Although, if this is for a class, keep in mind they may use an alternative formula with slightly different results (this is a simplified formula).
      950m is 3116.8 feet (my local measurement standard and the standard the formula was designed for) while 5895m is 19340.55 feet. 24C is 75.2F
      So, 19,340.55 feet – 5,895 feet = 13,445.55 change in elevation. Multiply that by 3.5, and divide by 1000, that’s 47.059 degrees change in temperature. 75.2F – 47.059 (initial temperature minus your change) and we get 28.141 F. Convert that back to C for your local usage, and that’s -2.144 C. Nice and chilly!
      Check my math, but that sounds about right. Let me know if any of that doesn’t make any sense.

  7. Nice,I feel like I learn something from you.
    Question:if the air temperature at sea level is 35 degree celisious,what would be the air temperature at 4000 meter above mean sea level?

    • I’m happy to hear I’m providing some new knowledge!
      First, we need to convert to Fahrenheit for my formula. 35C=95F. 4000 meters = about 13,000 feet. Sea level = 0 feet.
      3.5 x 13 = 45.5 degrees change. So, 95F-45.5=49.5F, or 9.7C. Brrrrr!

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s