Well "recorded" already narrows it down to the history of thermometers (largely 17th century and later), then the very first bullet point in the article mention

Well "recorded" already narrows it down to the history of thermometers (largely 17th century and later), then the very first bullet point in the article mentions that the dataset is 1880–2015, which really clears that matter up, I'd say. So, "useful" in the sense of "let me summarize the article in two words so you can reach your own conclusions instead of clicking that link and reading NOAA's". Semi apologies for the snark, but yes, the first comment really was an almost informationless attempt to derail. Success!