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The AI Weather Quest is a collaborative forecasting challenge hosted by ECMWF, designed to explore the potential of AI and machine learning in medium-range weather prediction. Participating teams are challenged with providing quintile-based probabilistic forecasts for three key variables: near-surface air temperature (tas), mean sea level pressure (mslp), and accumulated precipitation (pr). Forecasts target lead times of days 19 to 25 (week 3) and days 26 to 32 (week 4).
Starting 19 September 2025, the Leaderboards page will display:
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The Leaderboards page displays ranked Probability Skill Scores (RPSS) for submitted forecasts
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, as well as team and model rankings
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, through leaderboards and evolution graphs.
Evaluation results are indeed only are only made available after the evaluation date (day 37 of each competition week) has passed, on Fridays at 00:00 UTC.
This guide explains how to use the leaderboards page effectively and track the evolution of team and model performance over time.
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Filters apply to all elements on the page, including RPSS tables leaderboards and evolution graphs. By default, the page displays the latest evaluated period and week, the first forecast window (Days 19–25), and variable-averaged scores.
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- Variable-averaged (tas, mslp, pr)
- tas Near-surface (2m) temperature (tas)
- mslp (mean Mean sea level pressure (mslp)
- Precipitation (pr (precipitation)
Understanding the RPSS
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leaderboards
All rankings are based on the RPSS of each team's best-performing model. However, individual model ranks and scores are also visualised, allowing users to compare performance across multiple submissions from the same team.
Click any RPSS score in the table leaderboard to view the corresponding forecast in the ECMWF-hosted sub-seasonal AI forecasting portal.
There are two main types of RPSS tablesleaderboard:
1. Period-aggregated RPSS
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leaderboard
- Shows RPSS scores aggregated over a selected competitive period (e.g. SON 2025)
- Useful for assessing overall performance across multiple weeks
2. Weekly RPSS
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leaderboard
- Shows RPSS scores for a specific competition week
- Useful for tracking short-term performance
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- X-axis: competition week numbers within the competitive period
- Y-axis: team rankings based on RPSS of their best-performing model
- Default view: top 5 teams for selected filters
- Up to 10 teams can be selected at once
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