TheClimateChanger

A few notes on the edits: Using Martz's own data, I changed the format to recognize the most recent date on which a given high was set. Showing only the earliest occurrence, of course, is going to favor earlier years. For Maryland, I recognized the higher 106°F reading from Baltimore Science Center in 2012, which was omitted by Martz. For North Carolina, I added the 107°F tie from 2012 at a cooperative station that was missing from Martz's data. Note that several RAWS stations were even hotter, in the 107–109°F range, but I did not recognize those here. For Maine, Fryeburg and other coop stations reached 101°F in 2025, matching the value Martz had listed. Rachel Carson RAWS reportedly reached 103°F, but again, I went with the lower conventional station mark. For New York, I removed the absurd 105°F reading from 1919. No other station in New York was above 98°F that month. The site that supposedly reached 105°F is in the elevated northern interior, and on the same day several nearby stations reported highs only in the 88–92°F range. The same station also supposedly had a low of 50°F, implying a 55°F diurnal range. That reading is not credible. I used 104°F from 2012 instead, though even that may be too high. The next value would be 103°F, which was most recently reached in 2025. There are also a few older records that are probably questionable, but I left them in place because the goal here was mainly to update Martz’s map rather than fully reconstruct every state record from scratch. Pennsylvania’s 107°F from 1933 is almost certainly erroneous as it is far above surrounding observations. But I left it because the next-highest readings were either from that same year at other stations, including on the opposite side of the state, or from the same general era. In other words, changing it would require a deeper reconstruction rather than a simple update. Wyoming is another interesting case. There is a reported 114°F reading from 1988 that Martz rejects apparently because it was several degrees higher than other Wyoming observations. But that one does not strike me as obviously impossible. Montana set its state record in 1988, Minnesota tied its June record in 1988, and the Wyoming site was near western Nebraska, where there were observations in the 110–112°F range. Even if the 114°F were 3°F too high, it would still match the 111°F record from 1919 shown here. Note that the 111°F record recognized by Martz was also the highest by several degrees that month. So yes, there are likely other discrepancies and judgment calls buried in the record book. But the big picture does not depend on any one marginal station. Once you present the most recent tied occurrence, correct the obvious omissions/data issues, and add the 2025 New England records, the map changes dramatically.

This is what Martz’s June statewide high-temperature record map looks like if you present the most recent occurrence of each record, correct a few omissions/data errors, and add in the 2025 records that were set or tied across New England. With the updated/tied values included, 23 of 51 U.S. jurisdictions (50 states plus DC) have set or tied their statewide June high-temperature record in just the past 14 years, from 2012 through 2025. That is a huge chunk of the record book, especially considering that many of these records extend back into the 19th century. A lot of the changes come from the brutal 2012 heat wave, when numerous states tied or set June records. Then 2025 added another cluster in New England. The result is a map that looks a lot less like “the old records still dominate” and a lot more like what you would expect in a warming world: the upper tail keeps getting pushed higher, and old records keep getting matched or exceeded. Here is a table showing all June statewide record high temperatures set or tied from 2012-2025: State / Jurisdiction June Record Year Colorado 114°F 2012 Georgia 110°F 2012 Illinois 109°F 2012 Kansas 118°F 2012 Kentucky 111°F 2012 Maryland 106°F 2012 Missouri 112°F 2012 Nebraska 116°F 2012 New York 104°F 2012 North Carolina 107°F* 2012 South Carolina 113°F 2012 Tennessee 110°F 2012 Virginia 106°F 2012 District of Columbia 104°F 2012 Idaho 116°F 2015 Hawaii 96°F 2019 Oregon 119°F 2021 Washington 120°F 2021 Massachusetts 105°F 2025 Maine 101°F* 2025 New Hampshire 102°F 2025 Rhode Island 100°F 2025 Vermont 103°F 2025

Wow, not too bad north.

I didn't see anyone mention, but it was an incredible spring here for western Pennsylvania standards. The average high of 65.7°F ranked as 4th warmest on record for meteorological spring behind only 2012, 2024 & 1921. Incredibly, each of the last three springs are among the 8th warmest (by average daily high) in the entire threaded record! Wow!

After a relatively cooler start to the month, it looks like temperatures should be decidedly warmer than normal for much of the next two weeks. Here are the European ensemble means and spreads for highs & lows at Allegheny County Airport. Looks like great pool weather coming up.

Summer is here!

Just a touch of some Canadian smoke aloft it looks like.

And just to put this in perspective: NOAA has District 10 — southeast Lower Michigan — at the 23rd warmest January–April average low since 1895. DTW, meanwhile, is only 53rd warmest for the same period (1895-2026). Some of that is obviously tied to station history/site moves, but it illustrates the broader point: NOAA does not build climate averages from one airport thermometer. It uses the broader station network precisely because individual stations have siting, equipment, and continuity issues.

I think this misses the point. I’m not making a broad ASOS-era vs pre-ASOS-era argument. The issue is the ASOS sensor retrofit — Vaisala HMP155E probes replacing the older DTS-1 / HO-83/1088 sensors across the network. That rollout occurred last summer, so all of those Jan–May years are on the old sensor. The relevant comparison is before vs after the retrofit, not Jan–May rankings going back to the 1800s.

Withdrawal symptoms should subside shortly. Canada is reactivating the smoke machine as we speak.

This does not rebut anything. The claim is not “DTW should be colder than every nearby station.” The claim is that an equipment change can affect continuity in DTW’s own record. NOAA replaced ASOS temp/dew point sensors networkwide with the new Vaisala sensors/shields, and that rollout has been completed. So DTW, DET, YIP, and ARB are not some clean “control group.” They were all part of the retrofit. All you’ve shown is that DTW remains warmer than nearby stations. That’s siting/geography. It says very little about pre/post retrofit homogeneity.

The hypothetical only works by assuming the entire tropical ocean belt is +3.3°C above recent climatology, which is physically impossible. But yeah, in theory, if ONI were +3.3°C and RONI were 0°C, that would not mean “monster El Niño.” It would mean the entire tropical ocean was so absurdly warm that Niño 3.4 no longer stood out.

Oh yeah, I forgot: we’re only allowed to suggest modern readings may be biased warm. It is apparently anathema to point out that some sensor/site discrepancies could cut the other way — especially when the daily highs line up better than the lows.

A +2.7°C RONI peak may be comparable to 1982 in relative ENSO strength, but a +3.3°C ONI peak would still be physically meaningful because it reflects the actual SST anomaly humans, ecosystems, and the atmosphere experience. ONI already uses a rolling 30-year climatology updated every five years. So why is RONI still ~0.6°C lower? Because the entire tropical ocean background is running absurdly warm even versus the recent baseline.

The funniest part of this is that the goalposts move depending on which statistic is inconvenient.When I use mean temperatures, they complain that highs matter more because daytime warmth is what people actually experience. When I use maximum temperatures, they suddenly discover minima and diurnal ranges. There is a method to my madness here. Since the ASOS sensor/shield changes, minimum temperatures appear to be running unusually cool relative to the old observing regime, especially under radiational cooling setups. That means larger diurnal ranges can show up in the data in a way that is not necessarily apples-to-apples with the older record. That is why I have been emphasizing maximum temperatures more recently when it comes to ASOS readings. Highs are more likely to be consistent across the long-term record than minima that are especially sensitive to calm, clear-night radiational cooling and sensor/shield behavior. And, ironically, these unusually large diurnal ranges are the opposite of what you would expect if the signal were simply urban heat island or greenhouse-gas-enhanced nighttime warming. AGW tends to compress diurnal range by warming nights more than days. UHI also tends to show up most strongly in overnight minima. So yes, Detroit had a cold stretch. Nobody is denying that. But calling the winter some kind of grand rebuttal to the broader warmth is absurd. Year-to-date is still above average, March and April were very warm, and warmth has easily won the larger battle. You can cherry-pick January 15 to February 9 all you want. I can also pick March and April. That is why we look at the full context. But the rule cannot be: Mean temps matter when they help you. High temps matter when they help you. Min temps matter when they help you. And everything else is “spin” when it does not.

Exactly. A -2.6°F January departure against the warmest thirty-year normal on record is not some historic cold event. It does not even crack the top fifty coldest Januaries locally. In the old climate, that would have been a pretty ordinary, seasonably cold January. In today’s climate, people have become so used to warmth that a modestly below-normal month suddenly gets treated like 1977 reincarnated. That is the broader point they keep missing. Nobody is denying that cold shots happened, or that parts of the Great Lakes had a cool stretch. But it is pretty rich to accuse others of “ignoring the cold” while repeatedly ignoring the much larger and more persistent warm signal. From a historical perspective, it has been very warm year-to-date across much of the Midwest and Great Lakes, and even looking back over the last six months or so, since late November, warmth has easily won the battle. So yes, talk about the cold when it happens. That is weather. But pretending a ho-hum cold month or a two-to-three-day cool shot cancels out repeated warm pulses, record ridging, and months of above to well-above normal temperatures is not weather enthusiasm. It is selective accounting.

Wow! Nobody is “ignoring cold.” The point is that you’re cherry-picking cold pockets while acting like warmth somehow doesn’t count unless it happens in your backyard. Look at the actual regional year-to-date high temperature rankings: much of the western part of the subforum is top 5 warmest, with multiple stations ranking between 2nd & 5th warmest. Even farther east, places like Detroit, Cleveland, Columbus and Toledo are in the top 10 to 20 warmest for average daily highs, and those rankings are likely to climb with the ongoing warmth. So yes, there were cold stretches. It is still weather. But on balance, warmth has very clearly won out across the region. Only the far north has been more mixed. Calling that an “echo chamber” does not change the data.

Just some typical "no summer" doomerism from the usual suspects. In all seriousness, this looks like a warm start to meteorological summer.

This has been an incredibly warm spring. I guess some folks just won't be happy unless the temperature is in the 70s, 80s, and 90s every day.

The funniest thing about this whole nonsense is many of these "adjustments" (I don't think they are actually adjustments; data is smoothed across county lines) result in warming the past in many counties.