NOAA’s file does not just fill holes, which can be expected when dealing with large datasets. It also overwrites real readings at nearly every station. The replacements lean cool in the past and warm in the present, the same shape as NOAA’s adjustments overall, and in 2025 that includes a full year of readings at 29 working stations, Key West’s airport among them. To be clear, the estimates are not only for closed stations. NOAA’s file also replaces readings that stations actually recorded. This happens when NOAA’s adjustment procedure decides that a stretch of a station’s record is too short to correct reliably, as NOAA explained in 2014; it discards the readings and puts estimates in their place. From 1895 through 2025 there are 93,047 such months, at 1,217 of the 1,218 stations. The top chart answers a simple question: when NOAA replaces a recorded daytime high with an estimate, is the estimate warmer or cooler than the reading it replaced? Each bar is a decade. A bar below zero (blue) means the estimates in that decade were on average cooler than the readings; a bar above zero (orange) means warmer. The comparison is made after NOAA’s “reading-time correction” has already been applied to the readings, so the one adjustment NOAA has documented and tested is not the cause of what you see. The result is that in every decade from the 1890s through the 2000s the estimates are cooler than the readings, by roughly half a degree to a full degree Fahrenheit before 1980 and by two or three tenths of a degree from the 1980s through the 2000s. In the 2010s and the 2020s the estimates are warmer than the readings, by 0.06 and 0.33 degree. The bottom chart shows how many recorded months were replaced in each decade: between 5,000 and 9,000 in every decade through the 2000s, fewer recently. However, for 2025 the replaced readings include every single month at 29 stations that reported a full year of data, among them Key West International Airport, Baton Rouge Metro Airport, Astoria Airport, and the National Weather Service office in Blacksburg, Virginia. The number of such stations has risen from 6 in 2015 to 29 in 2025.

This is the first map of the ghost stations drawn from NOAA’s current data, and these 479 ghost stations represent 39 percent of NOAA’s network. This count comes directly from NOAA’s own file dated October 19, 2026. It exceeds the “more than 30 percent” figure Shewchuk gave a reporter in 2024 and is close to the 490 stations flagged on an anonymous map he circulates, which was based on NOAA’s 2022 files. This map shows the 48 contiguous states, with one dot for each of the 1,218 stations in NOAA’s network. The color and style of each dot indicate what NOAA’s file contains for that station for the year 2025. •Solid blue dots mark stations that recorded all twelve months of 2025 (547 stations). •Open circles mark stations that recorded some months of 2025, with the rest estimated by NOAA (192 stations). •Solid orange dots mark stations for which every month of 2025 is an estimate (479 stations). These are the “ghost stations” that retired meteorologist John Shewchuk has highlighted one by one: stations that no longer report data, yet for which NOAA’s file still carries a full year of temperature values. The orange dots appear across the country, not concentrated in any single region. They are densest in Oklahoma, Louisiana, the Northeast, and the Pacific Northwest, but every state has at least one. Of the 479, 242 have recorded no actual data since 2014 or earlier, meaning they have been estimated for more than a decade.