What is the #30DayMapChallenge?
The #30DayMapChallenge is a community mapping challenge that runs every day from 1 to 30 November. Each day has a theme, and you make a map for it and share it with the hashtag #30DayMapChallenge.
- No sign-up. You take part by sharing a map.
- Any tool is very welcome. R, Python, QGIS, or pen and paper, with or without AI.
- You don't need to do all 30. Pick one or two days that suit you. That is already a great result.
- It isn't a competition. Make your own work, credit your data sources, and enjoy it.
This special edition of the Coding Café gets you ready before the challenge starts. You leave with your first map already made.
Programme (90 minutes)
| Time | What |
|---|---|
| 0–5 | Welcome, and a quick poll: have you ever made a map in code? |
| 5–15 | How the challenge works and this year's themes |
| 15–35 | How a map gets made in code: data, projection, geometry, styling and export, in R (sf, ggplot2, tmap) and Python (geopandas) |
| 35–45 | Live demo: an AI agent builds a map, and we check what it got wrong |
| 45–85 | Hands-on: everyone makes a Day 1 "Points" map from the starter repo, then picks their own days |
| 85–90 | How to share your maps, and how to stay in touch during November |
AI is welcome
This year the Coding Café's theme is AI in research software development, so using an AI assistant or agent to help make your maps is supported. It isn't the main aim, though: the point is making maps, and maps made in R, Python or any other tool without AI are just as welcome.
Two days fit AI especially well:
- Day 10, "Prompting only": make a map from start to finish only by prompting an AI.
- Day 27, "New tool": a good day to try an AI agent in your mapmaking.
If you use AI, add one line per map saying how, for example: "AI wrote the plotting code, I chose the data and the projection." That keeps the maps honest and makes AI use something we can learn from.
Some of this year's themes
| Day | Theme | Day | Theme |
|---|---|---|---|
| 1 | Points | 16 | Collaborative map |
| 2 | Lines | 20 | Hexagons |
| 3 | Polygons | 21 | OpenStreetMap |
| 9 | Urban-rural | 22 | Projections |
| 10 | Prompting only | 26 | Water |
| 12 | Power | 27 | New tool |
| 13 | Interactions | 30 | Pen & paper |
The full list of 30 themes is in the starter repo and on 30daymapchallenge.com.
Before you come
Bring a laptop with R or Python. The starter repo has templates for both, an instruction file for AI agents, and a small Eindhoven dataset that is already downloaded, so you won't have to wait for anything.
Good sources of Dutch open data: OpenStreetMap, PDOK, CBS and Eindhoven open data.
Can't make it on 28 October?
You can still join: fill in the sign-up form and we'll send you the starter repo and updates during November. If enough people join, we'll also hold a show-and-tell at the end of November to look at everyone's maps.
Our neighbours at TU Delft, Rbanism, run their own R edition of the challenge every November.