A great day on the slopes depends on a specific combination of conditions, and the score is built around them. Temperature leads, but the ideal is a band rather than simply colder-is-better: cold enough that snow stays firm and dry rather than turning slushy, but not so brutally cold that being outdoors becomes miserable and frostbite a risk. The sweet spot sits a few degrees below freezing, where snow quality is good and conditions are comfortable enough to enjoy a full day. The score falls at both extremes, marking down bitter, dangerous cold as well as the above-freezing warmth that turns snow heavy and wet and, worse, brings the rain that ruins a snow surface.
Wind and visibility carry serious weight in the ski score because the mountain environment magnifies their effects. Strong wind not only chills you dangerously through wind-chill but can close the exposed upper lifts entirely, confining skiers to lower runs, and it whips up loose snow that cuts visibility. Visibility itself is a genuine safety factor: in a whiteout of cloud, fog or heavy snow, it becomes impossible to read the terrain ahead, judge gradients or spot hazards and other people, which is both dangerous and unpleasant. The score rewards the clear, calmer days when the whole mountain is open and you can actually see where you are going.
The score treats rain as strongly negative because rain is the enemy of good snow: it saturates and destroys the surface, turning it to slush that refreezes into treacherous ice, and it makes for a thoroughly wet, cold, miserable day. Fresh snowfall, by contrast, is what every skier hopes for, laying down the soft powder that makes for the best skiing, though very heavy snow during the day can reduce visibility and close lifts. The score's temperature and precipitation factors together aim to capture whether conditions favour good, skiable snow, but the deeper question of snow depth and quality on the ground depends on the recent history of the whole season, which no single day's weather can tell you.
Use the score alongside the specific information that mountains provide. Ski resorts publish their own snow reports, lift status and avalanche risk, and these are essential reading that the weather score complements rather than replaces. A high score signals good general conditions, but always check which lifts are open, how deep the base is and what the avalanche bulletin says before heading into any off-piste terrain, where avalanche risk is a serious, potentially fatal hazard that weather strongly influences. Dress in warm layers for the cold and wind the score accounts for, protect your eyes and skin from intense high-altitude sun and glare off the snow, and treat the mountain with the respect its fast-changing weather demands.