Weather Underground, a site that compiles local data collected by 24,000 weather geeks with sensors on their roofs, this week released a free tool for businesses to use to look for patterns in their sales related to the weather. Anyone can punch in a location and time period to download a spreadsheet with detailed weather data. The file also has a place to enter daily sales (which comes prepopulated with fake sales numbers) and charts that show the sales numbers in relation to temperatures, precipitation, and dew point (a measure of humidity). The spreadsheet calculates the correlation between sales and those three weather metrics to show which have a meaningful relationship.
Weather Underground’s main business since it started in 1995 has been targeting ads on its site for brands that want to reach consumers during certain weather conditions. Companies can, for example, offer getaway deals to Hawaii during nasty winter storms, or hawk lawn furniture and garden supplies on the first sunny weekend of spring.