Tracks snowstorms for skiers and boarders.
Cost: Basic membership is free. Pro accounts, $20 or $45 a year, get you add-ons like access to meteorologists and powder alerts for resorts you pick. opensnow.com
Chance of Weather
Select an activity—from biking to barbecuing—and plug in a zip code for hourly forecasts, along with rankings that grade the potential enjoyment of your chosen pursuit based on conditions.
Cost: Free. chanceofweather.com
Gives kiteboarders, sailors, and windsurfers minute-by-minute wind reports and hourly forecasts at more than 50,000 locations worldwide.
Cost: Free to view forecasts. Pro memberships – $3 to $10 monthly – feature real-time wind observations, daily meteorologist briefings, and unlimited e-mail or SMS alerts. windalert.com
Washington Online Weather
Offers high-altitude mountain forecasts for the Himalayas, the Alps, Denali, the Caucasus, the Karakoram, and the Andes. Reports are customized to match intended climbing routes.
Cost: From $45. Price varies depending on location and quantity of forecasts. wowweather.com
Select conditions—tornadoes, lightning, flash flooding, heavy snow, hail, high wind—and get notified if severe weather is in the vicinity. Ignore an alert for more than two minutes and a meteorologist texts you to ensure you’re safe.
Cost: Up to $20 a month per device. enterprisesolutions.accuweather.com
Stealth Travel Club
Get e-mailed when it’s about to go off at one of numerous world-class surf breaks. Book and pay to join a prearranged “surfari” and within 48 hours you’ll be charging bombers.
Cost: Free for forecasts; trip costs vary depending on destination. worldsurfaris.com