On December 17, 2024, the Southern California Edison weather station that is bolted to a powerline next to the Pinecrest Gate at Eaton Canyon observed something rather remarkable. At 10:50 PM, the station recorded an air temperature of 74.4°F as a 14 MPH Santa Ana breeze swept past it. This beat the previous afternoon’s observed high of 73.7°F, meaning the weather station set its daytime high temperature a full five hours after sun set in the month of December!
This early-winter warm spell has been part of a larger problem facing Eaton Canyon and Southern California in general this year. It is December 25th, and yet another week has gone by without any meaningful rainfall. Eaton Creek is running dry, soils are parched, and vegetation remains dust-ridden. The fourth wettest month of the year, December, will end as a total shutout in 2024 with no measurable rainfall at the official Pasadena weather station. This has only happened four other times in 118 years of precipitation record-keeping.
Having just come off our wettest 18-month period on record between November 2022 and April 2024, and our driest 18-month period on record between April 2020 and November 2021, this extreme precipitation whiplash is hitting local ecosystems hard. The 2020s have been marked by either feast or famine, and that trend has only continued. As a result of this, MyEatonCanyon.com can unfortunately report that hundreds of young Western Sycamore and White Alder saplings that sprouted alongside the creek following the uber-wet winter 2023 rains have perished. Some had attained heights of up to 8′ before succumbing to drought.
As it stands, Pasadena is currently experiencing its driest June 1st – December 25th period ever recorded with just 0.07,” besting the 0.11″ record set in 2020. At Eaton Canyon itself, just 0.13″ has fallen at Eaton Dam while up to 0.59″ has fallen at Camp Hi-Hill behind Eaton Saddle. These numbers are even worse than those seen in 2020 and 2017, both of which were other exceedingly dry years.
Taking a look at creek flow, however, flow extent still remains prevalent following the drenching rains of winters 2023 and 2024. As of the December 1st survey, 47.9% of the creek is flowing between the waterfall and the New York Drive bridge. This isn’t all that much worse than 2023, and many young White Alder and Sycamore saplings that are growing where the creek is still flowing are alive and well.
The long term pattern continues to look highly unfavorable for precipitation as a huge ridge of high pressure sets up over the eastern Pacific just off the coast of California. January 2025 already looks like it will also be a bone dry month, with few if any storms managing to break through.
Concerns about a significantly below average or even record dry winter in Southern California are mounting as Pacific storms continue to fall apart before reaching the region. MyEatonCanyon.com will continue to monitor the growing drought situation with monthly creek-flow surveys continuing as normal.
