In some cases, the weather is a huge factor. But how can you find reliable weather observations that would be admissible?
Look no further than the National Oceanic and Atmospheric Administration’s (“NOAA”, pronounced Noah) National Centers for Environmental Information’s Climate Data Online. What can you get? “[F]ree access to NCDC’s archive of global historical weather and climate data in addition to station history information. These data include quality controlled daily, monthly, seasonal, and yearly measurements of temperature, precipitation, wind, and degree days as well as radar data and 30-year Climate Normals.” Even better, “[c]ustomers can also order most of these data as certified hard copies for legal use.
Does it work? Yes, I once had a case where one key fact was the actual temperature on the side of a mountain at a certain time of day in summer. I placed an order and moments later received an email from NCEI confirming my order. Seven hours later, I received a 22 page pdf listing climatological observations from each weather station for the entire valley during the month. Certified copies were then requested of those stations most relevant. The best? No subpoena was needed.