Weather file URLs for DoE EPWs have changed

Hi Team

I’ve downloaded and installed 1.3.0 the component to import from URL returns the error 1.
Solution exception: Download failed with the error:
The remote server returned an error: (404) Not Found.

However when I check in 0.0.67 it’s accepting the URL as fine. I have randomly checked London and LA and these are working. The only difference I see is the ones returning the error have an EP URL and the rest have a Climate Onebuild URL. (384.8 KB)

Example problem URL :

Dear @chris, I have the same error.

This is definitely NOT an issue with the LBT 1.3 release and is happening because NREL/DoE changed the URLs of all of the EPW files in its database. Just make sure that you get your EPW URLs from the new and you should be fine:

We are working to update the URLs that are in EPWmap and we can post back here when they are updated.

FYI, the reason that the Legacy one seems to work is that you already have that particular EPW downloaded to your C:\ladybug folder and so the component is just loading that one instead of downloading it. The new LBT plugin reads the EPWs from a different location on your machine.

Alright, I realized that this is probably going to be a big headache for a lot of people so I changed the LB Download Weather component to just give you a warning when your URL is out of date and it will automatically convert the old URL to the new URL inside the component like so:

When you connect a URL in the new format, everything runs without the warning:

This issue seems big enough that I’ll update the LBT 1.3 Food4Rhino installer to ensure everyone gets the component that has this fix. I’ll post back here once the installer is updated.


Ok, the that downloads with Food4Rhino has been updated to include the change to the the LB Download Weather component .

This should help you a bit with updating your old scripts to use the new URL format.

I downloaded and updated from F4R. So I see the message giving the new path but it is returning:

  1. Solution exception: Download failed with the error:
    The remote server returned an error: (403) Forbidden.

I beleive from you message the updated component would fix the URL internally.
However I also copied the new URL to a new panel and plugged that into the component. I see the same error.

Ooriginal URL :

URL from component: 2.

Try one of those links: Onebuilding and EnergyPlus.
They work for me.

@AbrahamYezioro is correct. It looks like DoE did away with the IWEC version of the Mumbai weather file or maybe they just re-classified it (it’s now ISHRAE instead of IWEC). So, for this case, the URL needs to be reformatted AND IWEC needs to be changed to ISHRAE.

Also, @mostapha just finished upgrading EPWmap to have all of the new URLs so you should always be able to get the latest URL from there now.

Actually, scratch what I just said. It’s true that the IWEC file is not appearing in EPWmap but it’s still in the EPW database for the DoE. The issue is that there’s an additional formatting change for international EPW files in that we need to replace // in the URL with /. I guess this is because a lot of international URLs don’t have a state/province (which previously resulted in a blank //).

I’m working on a fix now. In the meantime, the new valid URL for Mumbai IWEC is:

Ok, the on Food4Rhino was just updated with this fix related to // vs /. So we should be good to go now.

Hi Chris

Just downloaded and tired. Its is now passing the weaterfile file. The only other element I see is the component is orange (but works) if I pass the C1B files in these are grey.

But thanks for the communicy support as always. Much appriciated.


Yes, @seanmoo . I purposefully made the component turn orange so that you are aware that the URL you are plugging is no longer valid and so you can manually update it. It’s not a failure message; Just a warning. The message in the orange balloon should be give you the correct URL to update to.

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Is someone able to help me. I am trying to find a zip file location for the chicago area, the URL is “” but it wont work and I cannot figure out what the updated link is. Is anyone able to provide that for me to enter into the weather URL of the “DownloadEPW”

@abraham85 here is the link to the zip for Chicago Midway.

you can use the ladybug epw map to get weather the file URL’s.

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@TrevorFedyna Worked like a charm, thank you!

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