TheClimateChanger

Record high of 90F at DuBois. That's the fifth consecutive daily record. Even for a relatively small period, very impressive. Good chance of matching or exceeding the monthly record of 92F, set on June 30, 1969, and earlier in this heat stretch (June 18, 2024). That's also 4 90+ readings on the year. For context, only 6 entire years since 1962 have seen more 90+ days, and this is only June 21! Those 6 years are: 1988, with 20; 2020 & 1966, with 8 each; 2010, with 6; and 2016 & 2011, with 5 each.

Baking today. PIT ASOS popping an 88F at 10:25.

Just checked MDT and it's the same story.

Yeah, I haven't noticed this phenomenon. At PIT, highs are actually more above normal than lows so far this month, with the diurnal range near 21F. I'm sure rural and outlying areas probably have diurnal ranges on the order of 22-24F this month.

While the thread creator suggesting sticking a fork in the month of June, Dayton International Airport observed its 4th consecutive 90+ reading today [coming off an 89F on Sunday]. The forecast calls for 90+ through Sunday, which, if it were to occur, would be the most 90F readings through June 23rd in any year since 1994. In addition, Dayton continues to impress from a temperature standpoint in 2024. The mean temperature through yesterday stood at 51.6F (and rapidly climbing each day of this heat wave). This is more than 0.5F warmer the second warmest year (2012). Of course, it's worth pointing out that the official observation site was still in the city, which can be as much as 300 feet lower in elevation than the airport, and with a significant urban heat island effect exacerbated by poor siting of the instrument on a building rooftop. Thus, it's likely that 2012 is actually the second warmest, but I digress. Between 1872 & 1996, 15 years at Knoxville saw mean temperatures [through 6-19] equal to or colder than Dayton in the year of our lord 2024. An additional 8 years in that interval were within 0.5F of the Dayton value. Whereas previously Dayton was performing better against Oklahoma City, the very hot summer climate of Oklahoma City is starting to leave Dayton in the dust. However, there were 6 years between 1899 & 1979 that were less than or equal to 51.6F [including one year (1979) that was a whopping 2F colder]. A total of 16 years in that same time interval are no more than 0.5F warmer than 2024 in Dayton. Based on this data, we can conclude that Dayton in 2024 is warmer than 1 out of every 8 years observed in Knoxville during the 19th and 20th century. We can similarly conclude that Dayton is warmer than about 1 in every 13 years in OKC during the first 4/5ths of the 20th century. Although this doesn't tell the full story, since Dayton is relatively warmer in the wintertime and OKC racks up massive numbers in the summertime. As such, it's very unfair to just look straight up since Dayton has a much milder climate overall than OKC.

Pennsylvania is also the new Knoxville, Tennessee. As noted above, KPIT is averaging 51.0F through yesterday [and rapidly climbing each day this heat wave continues]. Downtown Pittsburgh is likely between 52.1F and 54.8F. Just south of the Mason-Dixon line, Morgantown is at 52.4F and Hagerstown, Maryland is at 52.1F. At Knoxville, 6 years between 1885 and 1985 were less than or equal to 51.0F. 23 years between 1873 and 1996 were less than or equal to 52.1F. And 32 years were less than or equal to 52.4F. Using the predicted temperature for downtown Pittsburgh, an incredible 62 years - including as recently as 2013 - were less than or equal to 53.6F. Numerous other years had temperatures close to each of these values. Conclusion: Along the Mason-Dixon line in Pennsylvania, it is currently warmer than about 1 in 3 to 1 in 5 years in Knoxville, Tennessee that occurred in the late 19th and 20th centuries. In suburban Pittsburgh, it's likely warmer than about 1 in every 17 years, but in the urban core perhaps as warm as 1 in every 2-2.5 years.

Pennsylvania is the new Charlotte. At Pittsburgh International Airport, the mean temperature for the year through June 19 is 51.0F. Based on 28 years of data (1952-1979), the downtown city office averaged 2.6F warmer than the airport, with a range of +1.1 to +3.8F. Accordingly, we can surmise that the mean temperature in 2024 in downtown Pittsburgh has been approximately 53.6F, with a likely range of 52.1F to 54.8F. For context, KPIT is situated at 1200 feet ASL, whereas downtown Pittsburgh is 700-750 feet ASL [and the urban center of the metropolitan area]. At Charlotte, the mean temperature for the period 1/1 to 6/19 was at or below 53.6F on 17 occasions in the 98 years between 1885 & 1983 - or more than 1 out of every 6 years. An additional 9 years in that same time interval were within 0.5F of that value. Accordingly, we can conclude that the city of Pittsburgh in 2024 is likely warmer than about 1 in every 6 years in Charlotte through the late 20th century.

For the record, this analysis is based on the mean maximum temperature. I have been told in the past that it is the low temperatures making the summers warmer and that people judge summer months based on maximum temperatures. With the drought causing unusually large diurnal ranges, I thought maximum temperatures would probably be more appropriate for 2024.

Record watch starting again for June. Looks like some locations may see their warmest June on record. At Toledo, the mean maximum for the month stood at 84.1F through yesterday, which would be tenth warmest. With today's 95F factored in, the mean has climbed to 84.6F, placing it in a tie for ninth place. Based on the NWS forecast maximum temperatures, the monthly mean may climb to around 86.2F by the 27th. The current record is 85.9F, set in 1934 & 2005.

Sounds like Saturday is going to be a scorcher. 25th percentile NBM temperatures in the mid 90s, with H85 temperatures climbing to 22-24C. 75th-90th percentile temperatures must be pushing triple digits. Record highs are 95 for tomorrow, and 98 for Saturday (also the monthly record). Record max lows are 73F and 75F, respectively. The upper ridge will then begin to retrograde slowly on Saturday but still hold strong enough for one more day providing a continuation of the dangerous heat, and perhaps the hottest day with even the NBM 25th percentile suggesting mid 90s. Ensemble 850 mb temperatures still remain in the 22-24C range. Some records may be challenged. Due to the compounding effects, continued heat indices at and above 100 degrees, and the WPC heat risk tool showing major to extreme impacts, the heat headlines remain in effect through Saturday. That said, as with the past several days, some subtle weaknesses in the flow as the ridge axis pulls south could allow for isolated to scattered afternoon convection to throw wrinkles in the heat, but predictability in coverage and location is low probability at this time range.

000SXUS71 KPBZ 202007RERDUJRECORD EVENT REPORTNATIONAL WEATHER SERVICE PITTSBURGH PA406 PM EDT THU JUN 20 2024...RECORD HIGH TEMPERATURE SET AT DUBOIS...A RECORD HIGH TEMPERATURE OF 91 DEGREES WAS SET AT 3:53 PM EDT TODAY AT DUBOIS. THIS BREAKS THE OLD RECORD FOR JUNE 20TH OF 89 DEGREES SET IN 1991. THE TEMPERATURE MIGHT RISE FURTHER AND THIS RECORD REPORT WILL BE UPDATED IF NEEDED. THIS TEMPERATURE IS JUST 1F BELOW THE JUNE RECORD THAT WAS TIED ON JUNE 18, 2024. IN ADDITION, THE LOW THIS MORNING WAS 67F. THE RECORD WARM LOW TEMPERATURE FOR JUNE 20TH IS 66F SET IN 1996. SO UNLESS A THUNDERSTORM FORMS NEARBY AND COOLS THE TEMPERATURE BELOW 66F BEFORE MIDNIGHT, ANOTHER RECORD WOULD BE SET. $$CRAVEN

Up to 91F at the airport. My home station is baking but I think it gets heat from the balcony rail I have it installed on. Might still reach a respectable 92 or 93 officially today. I still think Saturday will probably wind up being the hottest day of this stretch. Should at least tag an official 3-day heat wave today through Saturday, with Sunday being a toss-up at this point. This area does seem to perform better directly ahead of the cold front, so I think if convection can hold off, we should be able to do it.

Site elevation is a big factor in that. A lot of Chester County is several hundred feet higher to as much as 1,000 feet higher in the hills. Would expect most places to be at least a couple degrees cooler to as much as 4-5 degrees in the highest elevations in the northern part of the county. PHL airport is basically at sea level.

Lots of red and brown out there. Just the way it ought to be in July. Even East Nantmeal might manage a couple of 90s.

Looking solid.

Should be able to reach 90 or 91. It’s already reached 87 or 88, and it’s quite a bit brighter than yesterday when it reached 89F. Still variable cloud cover, so one of those days if you get an extended intrahour sunny interval, it can shoot up a couple degrees then drop back.

Mount Washington Weather Archives - Mount Washington Observatory All the same extremes back to 1933, on the observatory archive.

xMacis only has the observations dating back to 1948. Not sure if anything higher was recorded prior to 1948.

Maximum of 70F yesterday at Mount Washington. 2 below the highest of record in June and all-time, since 1948. June All-time The minimum of 59F on the 18th was the highest of record since 1948 in the month of June and 1F below the all-time maximum. The minimum of 58F yesterday would have matched the previous monthly high. June All-time

While the current warm spell may have been a bit of a letdown thus far, it does appear increasingly likely that we see the warmest June on record at Pittsburgh International Airport, and a top ten warmest June in the threaded record. The number to beat at the current location is 73.0F from 1967. To get into the top ten overall, we would need a mean of 73.3F. There is a decent chance that it will be our warmest June overall since 1943, when the mean temperature was 74.5F. I estimate the mean should increase to around 72.9F through the 26th (based on current forecast) with continued warmer than normal weather likely thereafter.

Your car thermometer sensor is like a foot or so above black asphalt. I’m assuming that has more to do with this observation than “urban heat island” effect.

Looks like we’re going to be 89’d again like Sunday. Meanwhile, an all-time record of 96F in Caribou, Maine. Add northern Maine to the list of places that do heat better than Pittsburgh.

Yes, albeit many of the other local sites have reached 100+ due to slightly higher dewpoints. Almost impossible to reach official EHW criteria in the month of June at the airport. Only happened once since 1945 - June 27, 1978. The high that day was "only" 93F, so dewpoint readings must have been in the upper 70s to get that high of a heat index. Didn't even reach 105+ during 1994 or 1988, as humidity was relatively modest. I suspect NWS upgraded to EHW just due to duration and recognizing some of the lower elevation locations and the city probably have heat indices 2 or 3F warmer than the official values. Maybe we get closer later in the week or on Saturday.

The official temperature is taken to the nearest tenth of a degree in Celsius, and then converted to Fahrenheit (and rounded to nearest whole degree). The five minute observations read only to the nearest whole degree Celsius before the conversion, so due to rounding it can often be +/- 1F of what is shown. On sky cover, the METAR is augmented by a contract observer. The ASOS ceilorometer (sp?) only reports cloud cover at or below 12,000 feet. If the cloud deck is above that level, as it is this morning, the ASOS will report clear skies (which really only means clear skies below 12,000 feet). Also sometimes, it can miss some isolated lower clouds so you might see the ASOS report clear when it really should be something like FEW040 (a few clouds at 4,000 feet). None of the other ASOS or AWOS sites are augmented, so that's why PIT will often report much more substantial cloud cover than the other smaller local airports.