WEFEX - Weather & Seasonal Forecast Extremes
Know when extreme weather will hit, before it does
What is Wefex?
Wefex (Weather & Seasonal Forecast Extremes) is an interactive tool developed by Inside Climate Service (ICS) and the World Energy & Meteorology Council (WEMC) to quantify the probability of extreme weather events across Europe.
WEFEX answers a single, urgent question: how likely is an extreme weather event to occur, at this location, in this time window?
Rather than showing raw temperature or rainfall values, WEFEX shows the probability that conditions will exceed critical historical thresholds, framed against the ERA5 reanalysis record so you always understand what "extreme" means for your specific location and season.
It combines two complementary forecast systems, a short-range model for near-term operational decisions and a six-month seasonal outlook for strategic planning, all at daily resolution and flexible spatial scale.
How It Works
WEFEX layers two forecast systems to give you both immediate situational awareness and long-range strategic intelligence.
Short-range · up to 15 days
Operational precision
Daily forecasts from AI-driven (AIFS) and physics-based (IFS) ensemble models provide high-resolution insight into near-term extreme events. Essential for real-time decisions like grid management, harvest timing, or emergency preparedness.
Seasonal · up to 6 months
Strategic planning horizon
ECMWF seasonal forecasts extend your outlook to six months ahead, also at daily resolution. Anticipate resource needs, adjust investment strategies, and prepare for prolonged periods of climate stress before they arrive.
Who It's For
WEFEX is designed for organisations where extreme weather events translate directly into operational disruption or financial exposure.
Energy
Grid operators and renewable developers use WEFEX to:
- Predict wind gusts that could damage turbines
- Anticipate heatwaves that will spike electricity demand
- Plan maintenance windows around forecasted extremes
Agriculture & Water Management
Agricultural producers and water utilities use WEFEX to:
- Anticipate frost events threatening crops
- Flag extreme rainfall that could compromise harvests
- Identify drought conditions requiring resource reallocation
Insurance & Finance
Insurers and financial institutions use WEFEX to:
- Quantify the probability of claims-triggering events
- Support more accurate pricing and reserve planning
- Assess portfolio risk exposure ahead of extreme seasons
Infrastructure & Government
Infrastructure managers and civil protection agencies use WEFEX to:
- Integrate weather risk into maintenance scheduling
- Build emergency preparedness protocols on hard data
- Operate early warning systems for high-impact events
"From what I have seen, the tool is very good and useful, maybe more for a trained specialist rather than a basic user. It provides different information from other services and therefore has a real added value. From what I saw, the tool provides probabilities for more extreme events, while other tools generally focus on the probability of climatological terciles."
Laurent Dubus
Senior Scientist — RTE R&D, Climate, Long-Term Power System Adequacy and Planning Group
Key Features
- Probability thresholds — Not binary yes/no predictions, WEFEX gives probability distributions so you can assess whether a 20% chance of extreme wind justifies action.
- Multi-variable tracking — Monitors temperature, precipitation, wind speed, and wind gusts, the primary drivers of weather-related operational disruption.
- Flexible spatial scale — View highly localised gridded data or aggregate forecasts to province (ADM1) or country (ADM0) level, matching your operational scope.
- Intuitive visualisations — Interactive maps, historical comparison tools, and ensemble distribution charts make worst-case scenarios immediately legible.
Instead of "Tomorrow will be 34°C," WEFEX tells you there is a 27% probability of exceeding the 95th percentile, a level historically associated with extreme heat in your region. Every forecast is benchmarked against ERA5 historical percentiles, so risk is always shown in local context.
Ready to move from reactive to proactive?
Discover how WEFEX probabilistic intelligence can transform your climate risk strategy.