Hibiscus "Sunset Blvd"

On September 12, 2025, Kansas City reached a high of 97°F, which was significantly above the average high of 80.3°F for that date. 97°F was unusually hot for mid-September and tied for the 2nd-highest temperature ever recorded on that date in Kansas City history.

The culprit was a persistent Omega Block pattern:
A ridge of high pressure parked itself over the central U.S., trapping hot air and blocking cooler systems from moving in. The jet stream dipped on both coasts and surged over the Midwest, forming the Greek letter Ω — hence the name. This setup led to 15°F or more above-average temperatures across the region.

Why It Matters
These blocking patterns are notoriously stubborn, often lasting 1–2 weeks.
They’re linked to climate change, which is making such heat waves more frequent and intense.

Kansas City dipped into the 40s just last week. On September 6, 2025, the low temperature hit 49°F, and it hovered in the low 50s on surrounding days. That cool snap was part of a brief dip in the jet stream that allowed colder air from Canada to slide into the central U.S. This kind of temperature swing — from upper 40s to upper 90s within a week — is classic Midwest volatility, especially in early fall.