Heat Dome Diary: July 1-4, 2026
- Tal Galton
- Jul 5
- 4 min read
Updated: Jul 6
As I’ve mentioned before, I volunteer as an NWS COOP Observer, recording rainfall and temperature data for Celo 2 S, a station that dates back to 1948 – an unusually long period of data for a rural valley in this mountainous region. For its first 50 years, Celo’s records were kept by Elpenor Ohle, the founding physician of the Celo Health Center. This station pairs with Celo’s USGS river gage on the South Toe River (in operation since 1957).
Locally, the heat began to build on Wednesday, July 1 with a high of 93 F, the highest temp since a 95 degree reading at the end of July, 1999. In the end, this week's heat wave did not rival the hottest spell recorded for this weather station: during the last week of June, 1952, Celo reached 97 on three out of four days – the hottest days ever recorded here.
This past week, drier air jacked the temperature as the heat dome built (and gave us cooler overnight temps). Station CELO 2S hit 96 Thursday afternoon (officially the hottest recorded temp since 1952) and 95 on Friday. Prior to this week, Celo had only reached 95 or above 10 times in nearly 80 years. 9 out of those 10 days (now 12) occurred during the summer of 1952.
During the hottest stretch, overnight lows were around 60 degrees (as low as 58!), so we were able to bottle up that air and keep our house tolerably cool (w/out AC) all day long.
After 3 days straight of record highs, Celo 2S only reached 90 on July 4 (1 degree shy of 2024's high temp on that date). Here's an interesting stat, though: the high temp of 95 on July 3 was the 18th daily record high temp so far during the 2026 calendar year. If we lived in a stable climate, after 70 years of consistent record-keeping, we should expect to see about 5 record daily highs per year. Even before the recent heat wave, we had 15 daily record highs during the first half of the year, 6 times the expected rate.
As always, we are grateful for the headwaters privilege we enjoy up here in the South Toe Valley. The entire week was made of days straight from Crescent Dragonwagon's classic Ozark story, The Itch Book:
It's hot, we itch, the day's too long!
Something's wrong
but nothing
that a good creek dip wouldn't
fix....
Even at what may have been the highest water temperatures ever recorded for the South Toe (81 degrees near the Celo streamgage), the river was refreshing all week. The river has been near seasonal all-time lows for most of the spring and summer (this drought has earned its own forthcoming blogpost). Low flow, combined with extra sun due to Helene-scouring of river and tributary banks, makes for conditions that lend themselves to exceptionally warm water temps. However, it's quite possible the riparian zones are more forested now, even after Helene, than they were during that incredibly hot summer of 1952. The mountains and valley were considerably less forested back then, plus there were two major floods in the 1940s. South Toe Stewards installed 4 temp sensors (data must be retrieved manually) in the river last summer and recently conducted water quality testing as well -- the first testing of the South Toe in over a decade. We hope to be able to share those results in a publicly accessible format soon.
What capped the temp yesterday (Saturday, July 4) was the convection-caused cloud cover that ultimately resulted in a thunderhead over the northern peaks of the Blacks. We'll never know how much rain fell on the ridge between Gibbs Mt and Celo Knob, but we do know (thanks to the USGS gage positioned just below the White Oak confluence) that the muddy torrent of White Oak Creek (at about 3:45 pm) had more than 3X the flow of the entire South Toe River above White Oak!
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