The SendScore is a calculated metric (0-100%) designed to estimate the quality of a crag's climbing conditions based on weather data and specific crag characteristics.
It is calculated based on several factors. The score is not merely a snapshot of the current weather; it also incorporates dynamic models that consider past conditions, such as the drying process of wet rock after periods of rain.
Current rain is the biggest score killer. We also consider the probability of precipitation: even if it isn't currently raining, a high forecast risk lowers the score to reflect uncertainty.
Low humidity is almost always better for friction. High relative humidity reduces the score, making the air feel muggy and the rock feel greasy.
The score favors daylight hours. It ramps up at sunrise and ramps down at sunset. Climbing is encouraged to happen during the day.
We calculate an ideal wind based on the temperature. When it is cold, you want still air. When it is hot, a breeze is welcome to cool you down and dry the rock. However, extreme wind gusts are always penalized.
Similar to wind, the ideal amount of sun depends on the temperature. On very cold days, being in the sun is great; otherwise, you want the shade. We calculate sun-intensity at the wall and check whether it matches what the temperature calls for.
This factor comes from our dynamic moisture model. Shaped by the crag's characteristics, it reflects how recent weather conditions drive moisture absorption and evaporation throughout the rock material over time.
This is the "silent killer" of friction. If the rock temperature is colder than the dew point of the air, moisture will condense on the rock surface, making it wet even without rain.
Bouldering generally prefers cooler temperatures than Sport climbing, where a wider range of temperatures can be tolerable depending on sun exposure and wind. Scores drop as temperatures deviate from the ideal window for the specific discipline (too hot or too cold).
The SendScore is not just about the weather forecast; it is about how that weather interacts with the specific crag. Following characteristics are taken into account in our models:
We track the sun's position to determine when each wall is sunlit or shaded. A wall's aspect shapes sun comfort and how warm and dry the rock gets, so the score is computed separately for each orientation.
The steepness matters. An overhang or roof receives less rain than a slab or vertical wall, meaning it might stay dry during light rain.
Different rocks absorb water differently. Sandstone might act like a sponge (taking longer to dry), while granite might shed water quickly.
Trees shelter the wall from sun and wind. That shade keeps it cooler, but the blocked sun and wind also mean it dries more slowly after rain.
We don't just look at the current hour's weather. We run continuous simulations (state machines) for each crag orientation:
We simulate the thermal mass of the rock. It heats up in the sun and is cooled by wind, by the surrounding air and ground, and radiation to a clear sky at night. This is crucial for predicting humidity condensation risk on the rock surface.
We track how much moisture the rock holds — soaked up from rain, or even condensed straight from humid air — shaped by the rocktype and how sheltered the wall is. Wind, sun, and dry air then dry it out, letting us estimate how long the rock stays wet.
Often yes. North- versus south-facing, steepness, rock type, and tree cover all change how the same weather plays out — so even nearby crags can legitimately score very differently. It can also happen the other way around: if one crag is missing some of its characteristics, two places that are actually similar may still score differently (see Limitations).
Each wall aspect is scored separately: a sunny south face and a shaded north face on the same crag genuinely differ in sun, warmth, and drying. Use the wall-orientation selector on the crag page to switch between them.
Large crags can span several sectors with different aspects and surroundings, but a single entry carries only one set of characteristics — so the same vegetation, inclination, and rock type apply to all of it. The wall-orientation selector lets you pick the most relevant aspect, which covers the biggest difference. Storing each sector as its own entry with its own characteristics would be more accurate; we are steadily improving the database toward that, but a lot of manual work remains.
The rock holds moisture and dries only gradually. The model tracks that drying, so a crag stays penalised until it has actually dried out — not the moment the rain stops.
Other factors can hold it back: humidity, condensation risk, wind, temperature, or a high forecast rain probability. The "Why this score?" breakdown on each crag page shows exactly which factor is limiting it.
It's an estimate built from weather forecasts and modelled rock behaviour, not live sensors — so treat it as guidance, not certainty. See the Limitations below for the specifics.
No. A high score reflects friction and sending potential, not safety, and never replaces your own on-site judgment. See the Disclaimer below.
The SendScore is calculated for the entire crag and neglects route-specific features. Our models are not aware of seeping holes, tufas, bird droppings, bee nests, dirt from rare visits, loose rock, or other unforeseen condition killers on specific routes.
The score relies on weather forecasts which can be inaccurate. Furthermore, rock drying speeds and temperature retention are approximations based on general rock types, not real-time sensor data.
Accuracy depends on the correctness of crag data (orientation, rock type, altitude) in our database. Where crucial parameters are unknown, we use defaults which may lead to incorrect scores.
Climbing is an inherently dangerous activity. Always assess the risk and conditions of a climb yourself before starting. Do not climb outside if you lack the experience to judge safety and conditions independently.
A high SendScore indicates good potential for friction and sending conditions, not safety. Never attempt a climb you are not prepared for just because the score is high.
The SendScore is a tool intended to help experienced climbers identify the best potential climbing days. It does not replace common sense or on-site judgement.
Always respect local crag access regulations, potential bird bans, and parking rules. Inform yourself before visiting a crag.
The creators of SendScore assume no liability for accidents, injuries, or wasted trips resulting from reliance on this data.
Color Palette
Logo
UI Display Settings
Make daily/hourly scores bold in lists and charts
Show colored suitability bars under weather cards
Show sunrise and sunset times on the Sun Exposure card
Smoothly blend suitability colors instead of using blocks
Show colored glow around the main SendScore card
Show orientation selector inside the SendScore card instead of above it
Show colored SendScore timeline suitability bar inside the sticky top header
