TheClimateChanger

I went to the website cited in that article and generated this for KPIT. It uses available hourly data for the temp and dew point to generate a heat index. Extends back to 1945. According to this, since 1945, the maximum hourly heat index at PIT was 106F observed at 2 PM on June 27, 1978. Last week's heat wave tied the highest recorded heat indices for any June day (dating to 1945) for the 8 PM hour (96F) and 10 PM hour (91F). Keep in mind since this is based solely on hourly data, there could be a higher intra-hour reading. Here's the link: https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=153&network=PA_ASOS&zstation=PIT&month=jun&var=max_feel&_r=t&dpi=100&_fmt=png

Just heard a rumble of thunder here. Looks like we are going to get some much needed relief from the heat.

The ever a few degrees too hot sensor at Beaver County Airport in Chippewa Township is up to 96F. https://w1.weather.gov/data/obhistory/KBVI.html

It's a little bizarre really. The heat index at Youngstown is up to 105F, which is the highest heat index on record at that location in the month of June - surpassing the record of 104F set just last week. And there's not even a special weather statement, or mention in the hazardous weather outlook, let alone a heat advisory? It's difficult enough to realize heat advisory conditions around here. Source for record heat index (dating to 1947): https://www.wkbn.com/weather/heat-index-wednesday-hottest-in-at-least-75-years-in-june/ Current heat index is 105F (93F/75F temp/DP): https://w1.weather.gov/data/obhistory/KYNG.html

HRRR says upper 90s possible downtown tomorrow, with mid 90s around the airport. Would normally say these readings are unlikely but given upstream readings (was 100F in Toledo today), I'd say these aren't unreasonable.

Update… late day highs at Toledo and Cleveland. Toledo did reach 100, tying the record from 1988. Cleveland reached 95, matching the record set in 1941. Very similar spread to 1988 at Toledo. 100/61 today versus 100/62 on 6/22/1988. Tied the earliest 100+ reading at Toledo, and the low was one degree below normal for the date.

As of the 5 pm climate report, it appears to have stalled out at 99F. Interestingly, there was a 38F diurnal range (99F/61F). There was also a 38F diurnal range on June 21, 1988, when it hit 100F. Unusual to see a below normal low temperature on a day when the high is approaching 100 degrees.

Up to 98 degrees in Toledo, Ohio. Could be the first 100 there since July 7, 2012. If it does reach 100F, it would tie the daily record from 1988. It would also tie June 21, 1988 as the earliest 100F+ reading on record in Toledo.

Another 90 in Dayton. That's 5 this month, plus one 89F high temperature. Looks like a near certainty that there will be at least 3 more, and potentially as many as 5 more, by Sunday. That will bring the total to between 8 and 10 for June with several days remaining. Spartman must be thrilled.

Oh and I found copies of all of the 1895 Monthly Weather Review publications, which weren't scanned in by NCDC. They were published by the Franklin Institute and appear as an appendix to their annual report, accessible from the link below. These also have daily precipitation records, but not temperature or snowfall. Only monthly. The missing 1893, 1894, and 1896 reports can also probably be found using a similar search term on Google Books, but I didn't try to do so. https://www.google.com/books/edition/Annual_Report_of_the_Secretary_of_Intern/KENcBcN_-70C?hl=en&gbpv=1&dq=monthly+weather+review+july+1895+franklin+institute&pg=RA1-PA88&printsec=frontcover

These were from NCDC's Image and Publication System: https://www.ncdc.noaa.gov/IPS/cd/cd.html Just select Pennsylvania and choose the month. Unfortunately, Pennsylvania's publications are missing from March 1893 through March 1896 - not sure if that's because the State did not publish one for those months or if the hard copies were lost or destroyed. It looks like the publications begin in September 1887, but Coatesville was not included until March 1888. It was listed in the January and February 1888 publications, but no values published until March of that year. Records for West Chester go back to the inception of the publication.

He also appears in the Climatological Data reports for Pennsylvania beginning in March 1888, accessible from NCEI. Those reports also include monthly snowfall, which is not included in those Signal Corps reports. At least in the March 1888 report, they did not include daily temperatures and precipitation. But the reports do identify mean temperature, mean maximum temperature, mean minimum temperature, absolute maxima and minima, mean range, and maximum and minimum daily ranges, as well as precipitation, snowfall, sky conditions, and prevailing wind direction. In March 1888, the mean temperature was reported as 32.3F, with a maximum of 68.5 on the 31st and a minimum of -3 on the 6th. Precipitation totaled 6.28 inches, including 18.5" of snow. Skies were clear on 10 days, fair (partly cloudy) on 12 days, and overcast on 9 days. Prevailing winds were from the west.

Its not going to hold. The clouds and outflow dropped it enough that I’d be shocked if it didn’t drop to 74. The dew point is also down to 65 (as of the top of the hour) so leaves room to drop some more.

Surprised it's not a tornado watch, since the Day 1 outlook has us in the 5% zone.

While today's run of the Euro was oddly cool (apparently expecting more cloud cover), the 00z run looks very hot for next week.

12Z Euro only gets us up to about 84 today. Suffice it to say, that's wrong as it was up to 88 before 1 pm at the airport.

Yes, looks much drier and it appears there was a drought that summer. Looks like a lot of places had diurnal ranges near or even in excess of 30F. The climate seems much too humid and wet to achieve that today. 1988 was somewhat similar, but much hotter in general.

I couldn't find the raw data from where this was sourced. Environment Canada has the information uploaded, and also shows a subfreezing low on the 14th (-1.1C). A copy of the original record would probably help, as you'd be able to see whether an error was made in transcription. And the observer might have noted the frost or freeze if it occurred. However, it does not look like Environment Canada has these records readily available for download like NCDC. Looking at surrounding stations, it appears it was a cold morning as there were several reporting lows in the upper 30s to around 40. Not sure if this site was particularly good at radiational cooling, but could be a transcription error (like maybe it was written as 36 or 38, but difficult to decipher).

Here was Durham, Ontario, in July 1895:

Looks legitimate to me. I think people underestimate how cold it was in the 1800s. Some of the temperatures would be unfathomable today. This is July 1895 roundup for northern Ohio. New Waterford, Ohio had lows of 38 on the 3rd, 38 on the 4th, 37 on the 5th, 35th on the 10th, 35 on the 11th, 39 on the 12th, 37 on the 14th, 38 on the 29th, and 35 on the 31st. The mean low temperature for the month was 47.1F. It's rare just to fall below 50F these days anywhere in the State of Ohio during July. Having a monthly mean low temperature anywhere in the State of Ohio would be unfathomable. In addition, there were two other sites with mean lows in the 40s... Auburn (49.3F) and Norwalk (49.0F). The coldest low that month was 34F in Auburn on the 9th, but it looks like there low temperatures were shifted forward one day (i.e., the following morning low attributed to the prior day) as that reading is in line with the lows on the 10th, where there widespread low to mid 40s and several 30s. Frosts were recorded on the 4th and 10th that month in parts of the State.

94F, with a heat index of 107F at Dayton, after a high of 91F yesterday. Looks like a couple more days in the mid 90s this week, with heat indices well in excess of 100F at times.

It's coming. Heat index up to 113F at the John Glenn International Airport in Columbus, Ohio. Crazy gradient there in central and southeast Ohio along I-70. The current heat index in Zanesville, Ohio, 50 minutes from the airport, is 80F.

Just to illustrate this. The KPIT ASOS is at 40.5N, 80.27W. Here's the temperature at that gridpoint when it's printing the 97 in Pittsburgh.

One thing to keep in mind is the HRRR is a mesoscale model, so it's designed to take into account small features like elevation changes and urbanization. The 97 shown on the Pivotal maps is centered on downtown. Looks to top out around 94 at the airport, where official records are kept. That's not too unreasonable for a high end estimate, but probably more like 90 or 91, maybe 92, given model consensus.

8:00 A.M. EDT / 7:00 A.M. EST. Probably should have shown the prior map at 9Z (5:00 A.M. EDT/4:00 A.M. EST) for a pre-sunrise reading. It was about the same (82F in Pittsburgh).