Sign in to follow this  

Fsx weather (temps at high altitude)

Recommended Posts

hey guys


First thanks for all the help on here. I've been spamming the forums and getting a lot of great help!


However I find myself coming to the well again lol.


It's a little to well known fact that fsx' weather is buggy as heck. One of the classic problems is ridiculous temperatures at high altitudes +30 degrees Celsius at fl250 for example.


This of course causes a world of engine problems and "unfair" stalls.


I realized though today as I was flying at 16000 feet in the j41, that I was getting just terrible climb performance, so I immediately looked at the sat. But the problem is, I'm not really sure what is unreasonable temps for that altitude. I want to say it was like 8 degrees Celsius?


So what is an average range for that altitude? Even better is there a website, or resource that someone knows of where I can look up current RL METARS, for comparison?



Share this post

Link to post
Help AVSIM continue to serve you!
Please donate today!

Hi Inigo,


In the standart atmosphere (ISA) the temperature is at sea-level 15C, and it drops by 2C per 1000feet. 


An easy way to get you ISA temperature is to take 15 - (FL x2); in our case it would be 15 - (16x2) = -17 C


A small note to add is that the temperature becomes constant above the Tropopause, which in ISA conditions happens around 36080 feet and -56.5 C. The Tropopause is depicted on the high altitude weather chart in a box with a flight level inside. Because of the way the earth is heated it will be higher near equator and fall, in steps, towards the poles. 


I would recommend getting ASN for weather program for FSX.


Let me know if you have any further questions.

Share this post

Link to post

Hello Ingio,


Martin has said just about everything I would, I'd just like to add there is a freeware weather engine available at It's not as superb as ActiveSkyNext (ASN) but it's still good, especially if you'd rather spend the money elsewhere.

Share this post

Link to post

thanks for the advice I will look into ASN.  My PC is fairly powerful, but does ASN use a lot of system resources?

Share this post

Link to post



I suggest you head over here and get the free 7 day demo they have. Check it out, and adjust the settings for smooth operation.



Share this post

Link to post

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this