Warm Temperatures: A Record-Setting September in Kansas – Part 2
Last week, an eUpdate article focused on the lack of cool air during September. In part 2 of the September 2026 review, attention turns to the predominance of above-normal temperatures last month.
Statewide Temperature Record
Every day in September was above normal, according to data from the Kansas Mesonet. When all 30 days were averaged, the month finished around 8 degrees above normal. The average temperature for September across the Mesonet was 76.8°, exceeding the previous record of 76.7° set in 1931. There’s one important caveat: the Mesonet wasn’t around in 1931, so we can’t fairly compare 2026 to it. Instead, we rely on the National Centers for Environmental Information (NCEI), which has used climate data from our long-term airport and cooperative sites and has constructed monthly averages dating back to 1895. That’s where the 76.7° mark in 1931 comes from. The Mesonet average is a good estimate until NCEI issues their normals. October 8 was the release date for September’s data, and… drumroll please… the official number from NCEI for September was…77.3°, making 2026 officially the warmest September on record! For now, at least. Let me explain. Each month, when NCEI issues averages for the past month, they can also update previous months based on late-arriving data or problems with data not discovered at the initial data release. They can update a previous month up to 2 years after the initial release. The keyword here is ‘can’. I haven’t seen many updates more than two months after the initial release, and even then, they tend to be slight adjustments to average precipitation rather than to temperatures. If I waited two years to write this article, September 2026 would be merely a memory, so I’m stating the disclaimers up front. Even if something were to happen to the state record, there are plenty of individual station records set last month that are worth spotlighting.
Location Temperature Records
Like the state record, 1931 was the year to beat at most locations. While many stations had a record-warm September, it isn’t as impressive if the record isn’t compared to 1931. Therefore, I am limiting my comparisons to locations with at least 100 years of climate data that are still operational to ensure that 1931 is included. As restrictive as that sounds, Kansas has nearly 70 locations with at least a century of data. Unfortunately, some were unusable this past month due to missing data. After those were removed, the count of eligible locations was 51.
Let’s start by looking at what year held the September record prior to 2026 at those 51 locations. For more than half of them (31), that year was 1931. A number of other years held September records, including 2019 (6 sites), 1939 (6), 1954 (3), and five additional years (1905, 1911, 1978, 1998, 2015, all with 1 site). How many of these 51 locations held onto their record for September? Just over half: 27, leaving 24 new September records set. Of the 24 new records, only 8 unseated the 1931 record. The other years that held records were less successful in fending off September 2026; only two records from 1939, and one from both 1954 and 2019, remain standing. Table 1 lists the new records set.
Twelve of the 24 new September records were set by at least one degree, and two were at least two degrees above the old mark: Beloit (+2.1°) and Ashland (+2.0°). For those who missed out on a new record, many were close: 12 of the 27 sites that failed to set a new mark for September missed by one-half of a degree or less. For most of these locations, 2026 earned a runner-up finish, but four had to settle for a bronze medal as third warmest.
The record for Kansas’ warmest September was set in Norwich, in Kingman County, back in 1998 at 82.0°. Sedan came very close to that mark this year, averaging 81.8°. Sedan started September with 10 consecutive daily highs of 100 or better, peaking at 106° on the 10th. Ashland had the most 100-degree days in September with 15. Independence had the most 90-degree days this past month with 21, beating Ashland’s count of 20.
For stations with shorter periods of record, lowering the threshold to at least 50 years of data yields 59 stations setting new records for warmest September. Eighteen of these set new records by at least two degrees, led by Kirwin Dam in Phillips County, where the margin of victory in 2026 was an impressive 4.6° over 2021. This is one of seven sites where the new record was at least three degrees above the old, but none of those had to compete against 1931.
Table 1. List of stations with 100 or more years of climate data that set new temperature (˚F) records last month.
|
Location |
Sep. 2026 Avg. |
Old Record (Year) |
Year Records Began |
Location |
Sep. 2026 Avg. |
Old Record (Year) |
Year Records Began |
|
Wichita |
80.6° |
79.4° (1931) |
1888 |
Anthony |
80.6° |
79.9° (1931) |
1899 |
|
Horton |
75.0° |
74.9° (1931) |
1891 |
Ashland |
80.4° |
78.4° (1905) |
1900 |
|
Beloit |
76.9° |
74.9° (2019) |
1893 |
Elkhart |
75.8° |
75.6° (1931) |
1900 |
|
Sterling |
79.0° |
77.2° (1954) |
1893 |
Healy |
75.8° |
75.4° (2019) |
1901 |
|
Washington |
76.1° |
74.4° (2019) |
1893 |
Plainville 4 W |
76.9° |
76.4° (1931) |
1904 |
|
Sedan |
81.8° |
80.2° (1939) |
1893 |
Garnett 1 E |
78.5° |
76.7° (1978) |
1906 |
|
Tribune 1 W |
73.9° |
72.9° (1931) |
1893 |
Kingman |
80.1° |
78.9° (1954) |
1907 |
|
Syracuse 1 NE |
75.5° |
74.8° (2019) |
1893 |
Hill City |
76.3° |
75.9° (1939) |
1907 |
|
Lakin |
77.4° |
76.8° (2019) |
1893 |
Russell Springs |
74.8° |
73.4° (1911) |
1910 |
|
Independence |
81.0° |
80.4° (1939) |
1893 |
Cimarron |
79.0° |
77.3° (1931) |
1911 |
|
El Dorado |
81.2° |
81.0° (1931) |
1893 |
Smith Center |
76.0° |
75.3° (1998) |
1912 |
|
Osage City |
77.1° |
76.3° (1939) |
1896 |
Atwood |
73.4° |
72.2° (2015) |
1920 |
Matthew Sittel, Assistant State Climatologist
msittel@ksu.edu