A new CDS soon to be launched - expect some disruptions


Hello, is it possible to have a more exact date on the new CDS launch?
Right now is impossible to download even the smallest file and my work is stuck, since Ineed some files form ERA5 on pressure levels.
I hope for a fast reply.

Best regards,
Iason Markantonis


Hi, the latest update from our technical team shows the new CDS will become available in beta in coming weeks. As soon as we have a date, we will let users know. So stay tuned!


Nothing can be downloaded from CDS.
Both from API and from web-interface.
“Connection to download-0016.copernicus-climate.eu timed out.”
From 01.04.2024 8:20 GMT.
When this problem will be solved?

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Despite ongoing disruptions, the CDS is now once again delivering data volumes near to its full capacity (as shown on CDS Live).

However, CDS performance is linked to users’ behaviour. To help alleviate the longer than normal waiting times, a decision has been made to implement an additional temporary measure to ERA5 and ERA5-Land hourly (single level/pressure level) data requests from now on until the use of the new data infrastructure is fully optimised.

All data requests asking for ERA5 and ERA5-Land hourly data will now be restricted to a value of half of the previous limit. The new limits will be 60000 ‘items’ and 6000 ‘items’ respectively, and these limits will apply to both CDS web form and CDS API requests.

Please note that we advise users to request one month of ERA5 or ERA5-Land data at a time, as this is the most efficient way to request these data from the CDS. The CDS web forms for these datasets will also be modified to implement this restriction.

We therefore ask all users to follow our guidelines. As a result, the CDS performance will improve, and our technical team will continue to optimise the new infrastructure in preparation for the release of the new system.

We sincerely apologise for these temporary restrictions; however they will lead to an improved service for all users.

ECMWF Support

Dear @Michela could you all please clarify what counts as an “item” from the perspective of an API? I have no idea if my current request structure exceeds 60000 / 6000 or not.

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Hi @Robert_Banick,
the easiest way to check is to go to the relevant CDS web download page (e.g.
ERA5 single levels and form a request. As you increase your selection (more dates/times/variables), there will come a point when you exceed the limit and will see a warning message.
For ERA5 hourly data, an item corresponds to 1 variable at 1 level at 1 time, so for a single month you could ask for around 80 variables (all days, all times) in a single request.

I’ve tried using the CDS API again after many months of consigning it to ‘unusable’, but it’s still so unbelievably slow that it’s still unusable.

You could host it on AWS cloudfront, the data egress costs would be lower than standard S3, and it would be very quick (since subsequent requests would come from AWS’s caches rather than your own S3 bucket). Is there any further update on timelines?


I am (very slowly) downloading the ERA5 data and I run into a glitch in the data that I am not sure if it is due to these disruptions. For the data of February 2024 for my domain (Caribbean region) I am getting empty data fields after a few hours into the month for variables TP, STRD and SSR. I tried to download it again a few times, and I always get the same results. Does anyone know what could be the problem?
Best wishes,

please have a look here: ERA5 CDS requests which return a mixture of ERA5 and ERA5T data

No further informations about Downloads? I still cant download over 31 years of data in one go/ Had to change my work (climatology/Anomalies) to just few Heatwaves and coldwaves. However, I really want to download those over 31 years of data so I can work on climatology and not weekly anomalies.

im trying to download some data from the CDS but its sort of taking forever to que…which normally takes very little time, im aware CDS is undergoing a transformation. im a student and im in dire need of downloading some data for my FYP, can i know other ways of downloading the data quickly and effectively? thanku

It is not clear from the message regarding the recent changes if submitting requests for monthly periods should have higher priority in the queue and thus be faster than other requests that are yearly/other periods. A few days ago I submitted jobs to download a 6 month period in each job that were much faster than the jobs that I’m requesting now that uses monthly periods. Can someone elaborate concretely what is the most efficient way to download the data ? It is very slow to download even from a small region and a small set of single-level variables.

I am experiencing the same thing. I have been downloading ERA5 land-hourly surface_net_solar_radiation for the past two day, and just getting 1 or 2 files per 6 hours up to today, Friday 31st May (Malaysia).

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It is becoming impossible to download data to be honest, I have jobs for 1 month of data that are 13 hours in queue already and some are now failed with the error below:

I have the same issue.

Many (15+) hours in queue, then failed with “disappeared” or “Admin cancelled”.

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Honestly this is just unfair and wrong. How many more months will we have to wait? Many of us need those data to finish TCCs or anyother work, and so far we had no answer. For nearly 4 mothns I am trying to download 61 years of data for nearly 15 variables and I cant. Downloading 1 year at a time isnt doable.

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There is an ongoing issue on the Climate Data Store - please refer to our separate announcement on this: Major technical issue on the Climate Data Store
Thank you
ECMWF Support

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I understand that but my issue is:I need to download data from 1961-2020 for june/july/august in order to study Heatwaves and cold waves during South America (Brazil) winter, however, I cannot select more than 1 year at a time, and hence I have to download each variable (14 in total) separately , which is delaying my TCCs indefinitly, as I am facin over 2hs of waiting time for each variable. I really want to know if there is any news or expectations on full release of CDS, and when are we going to be able to download more than 1 year at a time , that would greatly help me further develop my TCCs in a more acceptable time schedule. Over the last 4 days I was able to download 1961-1962-1963 ans 1964 data, and that is not fast enough to finish before december.

Do you have any updates on the new CDS?


Please refer to our separate announcement: Informative page in readiness for new CDS-beta!