FAQ - ESoWC 2021

Q: What is ESoWC?

ECMWF Summer of Weather Code is a collaborative programme where each summer several developer teams work on innovative weather- and climate-related open-source software. ESoWC is organised by the European Centre for Medium-Range Weather Forecasts (ECMWF) and supported by Copernicus.

Q: How can I apply?

Go to ESoWC’s application form, choose the Stream (and if applicable the challenge) under which you would like to submit your proposal, agree to ESoWC’s Data Protection and Privacy statement and click on ‘Submit’.


Before you submit your proposal, you might want to see our tips on what makes a good proposal:

   • it is well structured and precise

   • the solution proposed is technically feasible within 4 months

   • it contains a clear timeline with milestones and deliverables defined

Q: Where is it?

It’s an online program, so you can take part from anywhere in the world.

Q: Who can apply?

The program is open to everyone. For Copernicus funded challenges we request however that participants are nationals from an EU or ECMWF Member State. If you are interested in learning and working with ECMWF’s software and data or want to apply Machine-Learning and AI to Copernicus data, you can have a look at the challenges on GitHub and submit a proposal to the challenge you are most interested in.


You can apply as an individual or as a team. If you are registering as a team, we ask that one team member registers with a personal email and you indicate the other team members in the form.

Q: What project would I work on? 

Possible projects that you can work on will be published on GitHub as issues. The idea is that you can ask clarifying questions in order to tailor your submission. The idea is that you can ask clarifying questions in order to tailor your submission. At the same time, these questions might be also useful for others interested in the challenge.

Q: What is the selection process? 

The submitted proposals will be evaluated by a committee based on the following criteria:


   • Comprehensibility

   • Clarity and structure

   • Feasibility

   • Easy to maintain / Future-proof approach

   • Innovative approach (if applicable)

   • Transferability (if applicable)


The programme committee can give your proposal in each category up to five points. The proposals with the highest overall number will be selected.

Q: What will I get out of this?

There are many reasons to get involved in the ECMWF Summer of Weather Code program. It is a great opportunity for you to meet meteorology, climate, atmosphere, machine-learning and cloud computing experts and showcase your skills in front of professionals in the industry. Teams selected for project developments will receive a £5,000 stipend.

Q: What are the the ESoWC streams?

There are three different ESoWC streams under which you can submit a proposal:

1. Software development for weather, climate and atmosphere*
Are you a weather enthusiast, software developer or a data wrangler? Check out the six challenges proposed related to the development of weather-related software and applications. Let us know your innovative ideas related to one of the challenges.


2. Machine Learning for weather, climate and atmosphere*

Are you a Machine Learning enthusiast or a Data Scientist? Check out the four challenges related to Machine Learning and Artificial Intelligence and let us know how you would solve one of the challenges. 


3. Visualize weather, climate and atmosphere*

Are you a passionate about data visualization? Check out the three challenges proposed related to the development of weather-related software and applications. Let us know your ideas how you would visualize weather, climate and atmosphere data.

* Successful projects will be eligible for a stipend of £5000 and if applicable, cloud credits from the European Weather Cloud or WEkEO. Please see individual challenge descriptions for more details.

Q: How many participants will be selected? 

A total of up to 10 projects may be selected.

Q: Does it cost to apply? 

There is no cost involved to apply and participate in the program. 

Q: What are the key dates and deadlines? 

   • Application deadline: 16 April 2021

   • Announcement of selected proposals and participants: 30 April 2021

   • Project development: From 3 May to 31 August 2021

   • Final ESoWC Day @ECMWF: 29 September 2021

#ESoWC2021

Let's Innovate Together