San Francisco Chronicle - (Sunday)
In September 1904, weather even wackier
This month has felt like a never ending series of extremes.
At the beginning of September, Californians endured a historic heat wave, with a week and a half of sweltering temperatures. A slew of all-time temperature records were broken across California and in the Bay Area. The largest wildfire of the year broke out in Placer County on Sept. 6 and jumped into El Dorado County, spurring evacuations for thousands of people.
Then the rain began. Tropical Storm Kay traveled unusually far north along the Baja California Peninsula and brought heavy downpours to Southern California, caus
ing flash flooding and mudslides. Last weekend, storms buffeted by typhoons in the western Pacific brought uncommon September showers to the Bay Area.
Such dramatic swings in weather can happen when the jet stream — a sinusoidal track of west-to-east winds miles above the United States — is extra-wavy.
“Next to big ridges, you have big troughs,” said Jan Null, a meteorologist with Golden Gate Weather Services and adjunct professor at San Jose State University. When these swings come back to back, unusual weather events can occur one after another. The recent heat wave was caused by a ridge of high pressure while rain this week has been caused by a trough of low pressure.
Similar conditions may have driven an even weirder September over a century ago.
“That I think is probably what happened in 1904,” Null said.
First came the heat
San Francisco has only ever recorded 15 days with triple-digit temperatures — and two of them were in September 1904. On Sept. 8, it was 76 in San Francisco at 7 a.m. and 100 by 2:30 p.m., The Chronicle reported the next day.
“Yesterday was the hottest day ever experienced in this city, and, succeeding a day which broke all previous high temperature records, the people of San Francisco felt the heat more than they had ever felt it before,” read the story on the third page.
Sept. 9 would be even hotter, registering 101 degrees — the tenth hottest day ever recorded in the city.
Amid the hot and dry conditions, wildfires raged in the Santa Cruz Mountains.
While temperatures in San Francisco didn’t break records in September 2022, the Bay Area hit an all-time high of 116 degrees in Fairfield and Livermore. On Sept. 6, Santa Rosa set a record 115 degrees, and on Sept. 8, San Jose hit an alltime high of 104, breaking a record that had stood since 1904.
Even amid the heat that year, Weather Bureau forecaster McAdle, referred to by The Chronicle as “Weather Prophet McAdle,” warned that the weather would be changing drastically. Fog was sitting offshore.
“I would advise everybody, visitors to the city in particular, to be constantly prepared to put on heavier clothing and overcoats. The may sound ridiculous with the temperatures at 100, but the moment the wind ... is strong enough to bring in the fog which lies out beyond the Farallones there will be a big drop in temperature,” McAdle was quoted as saying.
In a few days, the weather dropped 43 degrees.
Then came the rain
Two weeks later, the weather took a dramatic turn.
Between the night of Thursday, Sept. 22, 1904, and the next morning, an astonishing 2.9 inches of rain fell overnight in S.F.
The most high-profile damage was to the Ferry Building, where workers installing a new slate roof had left debris that clogged the storm drains and caused leaks inside, “ruining the walls, spoiling the heavy carpets and doing much injury to many valuable maps hanging on the walls,” reported the Sept. 24 edition of The Chronicle, “The loss incurred is estimated to be about $5,000.”
So many San Franciscans pulled fire alarms because of flooded basements that San Francisco Fire Chief John H. Dougherty got permission from City Hall to arrest people for pulling false alarms. Two San Francisco parades were canceled, including the beloved Odd Fellows Parade on Sept. 25.
One activity wasn’t canceled: baseball games. Games at 15,000capacity Recreation Park at Eighth and Market streets continued, with the Oakland Commuters beating the Los Angeles Angels 3-2. The teams combined for eight errors on the slippery field, The Chronicle wrote on Sept. 25.
The next day’s paper reported terrible playing conditions when the teams met again: “At the end of the fourth inning the rain shot down in torrents.” The crowd called for the games to stop, but owners insisted play continue until the end of the sixth inning, so they wouldn’t have to give a refund. Players wore coats through those two innings and were soaked to the skin.
It rained 5.07 inches in San Francisco over the course of the storm, making that month the wettest September on record for the city. While there has been measurable rain in the city for 64% of Septembers in the past 173 years, fewer than a dozen have registered an inch or more of rainfall.
“It’s probably going to be one of the top 50 rainfall events over 173 years,” Null said.
The rain in September 2022 has been less noteworthy, but still impressive. The 0.33 inches of rainfall on Sunday, Sept. 18 in downtown San Francisco substantially exceeds the normal precipitation of 0.10 inches for the month.
But the downpour in 1904 was extraordinary, as elaborately described in a Chronicle story from the time.
“Jupiter Pluvius continues his playful pranks, keeps the floodgates of heaven ajar and has poured his liquid blessings upon California in such superabundance that the people have become alarmed lest the paradise of the Western Hemisphere be deluged,” the paper wrote on Sept. 25. “The present storm has broken all records in California, and the end is not yet in sight, according to the soundings of the Weather Bureau.”