Quick take:
National Weather Service meteorologists say they cannot determine whether Santa Cruz set heat records during last month’s extreme temperatures because a 130-year-old volunteer-run climate station — the only site meeting strict long-term data standards — stopped operating in 2022, leaving a gap in the official record despite widespread unofficial measurements from other local sensors.
Watsonville, San Francisco and Salinas, like much of California, saw record-breaking temperatures during last month’s heat wave. But were records broken in Santa Cruz?
No one seems to know, because that data has not been collected since 2022.
That’s where the going gets a bit weird. This saga involves the National Weather Service’s rigid data-collection techniques, the essential role played by backyard weatherologists, and whether the data gap is that big of a deal in the first place.
The tale begins with one local National Weather Service weather station – in a volunteer’s backyard – that recorded daily temperatures since at least 1893, but died in 2022.
NWS meteorologists told Lookout Santa Cruz that, without a strictly regulated station recording daily temperatures in that same vicinity since, they can’t reliably say if Santa Cruz had record-breaking heat last month.
“We’re data people … We don’t make up data,” NWS meteorologist Brian Garcia said. “So anything since 2022, we’ve got nothing for Santa Cruz. We have no observational record for Santa Cruz there.”
To be considered an official climate station, NWS weather stations must adhere to a specific list of specifications, including that they haven’t moved more than five miles from its original location for at least 30 years — the threshold to observe long-term climate trends. No weather stations in Santa Cruz meet this standard. The one that did, stopped running four years ago. And the weather service has struggled to find a volunteer to take on the job of a new station in the same area.
“I’m a data nerd, and I live in Santa Cruz, so I miss it,” Garcia said. “Anytime any sort of professionally maintained weather station [is gone], I think it’s a loss – because at the end of the day, I want to go digging in data. I don’t want to go digging in hopes and dreams.”
While some news stations reported record-breaking temperatures, the reports didn’t include exact numbers for Santa Cruz from the NWS because, as Garcia stated, they had none. KSBW meteorologists reported Santa Cruz had an all-time high of 94 degrees for March, but noted on air that the temperature was pulled from an “unofficial” site.
Without this detailed data, the NWS loses the ability to compare events and mark climate changes. The meteorologists are steadfast in their methods and follow rigorous standards to ensure that the data has the lowest amount of variability possible.
Robert Lund, a UC Santa Cruz statistician who studies weather events, disagrees.
“I think they’re giving you a cop out,” Lund said. “All you do is you go up to another gauge, you get the record.”
About weather stations
The NWS is an agency under the U.S. National Oceanic and Atmospheric Administration (NOAA) that provides free, public weather and climate data. The agency collects data using a range of tools and equipment that provide varying levels of accuracy – from NASA satellites to the backyard weather enthusiast’s $950 temperature sensor and rain gauge systems.
The Cooperative Weather Observer Program, established in 1890, was created to collect daily weather data to track climate changes and provide it quickly so the public can use it for forecasting and safety. Volunteers collect the data from equipment that measures maximum and minimum temperatures, 24-hour precipitation totals and wind.
There are an estimated 3,000 co-op sites across the county. Some have been on family property for generations, while others are public buildings, such as water treatment plants or fire and police stations. About 200 volunteers resign or pass away each year.
Since the Santa Cruz volunteer couldn’t continue running his station, the weather service has struggled to find a replacement. To fit the criteria, a new station must be located within a five-mile radius of the original location in the Morrissey Avenue and Highway 1 area of Santa Cruz.
“It’s a big commitment. The weather happens every day,” said Ryan Walbrun, the NWS Cooperative Weather Observer Program lead for the San Francisco Bay Area region. “Even the most dedicated weather enthusiasts like to go on vacation sometimes.”
When the last volunteer stopped in 2022, Walbrun said they unsuccessfully tried to find a replacement through word of mouth and social media posts.
Walbrun said the equipment they use is the same at each of the sites across the country, which is one of the numerous ways the NWS works to minimize variability in the data. He said the equipment has been the same for 20 years or so and hasn’t been updated to include a system that can send data automatically. Instead, the user has to upload the data every day.
Walbrun said if they change equipment at a site, it will create subtle shifts in its results. So if they replace one, he said, they have to replace each of them across the country.
“Our goal is to keep it consistent from site to site,” he said. “So that when people are looking at the data, they can at least say the instrumentation is the same and not rule that out.”
The weather stations, which most often include temperature sensors and rain gauges, have similar placement requirements. For example, the temperature sensor needs to be placed at 5 feet plus or minus 1 foot above the ground and be at least 100 feet from a paved or concrete surface.
“We don’t want [a temperature gauge] in direct sunlight, on a roof or completely shaded under a tree,” he said.
He said the weather stations and their long-term records are important for marking significant weather events – like a record-breaking heat wave.
“We’ve had a long-running record of climate data at a place like Santa Cruz,” Walbrun said. “You have a March heat wave, you want to compare it to past events, and now, we literally kind of can’t.”
Lund, the UCSC statistician, said it’s common for these stations to go on and offline but it’s not something he’s worried about.
“I’m not going to lose sleep over losing one climate station,” he said. “If you told me I lost 500 in the state of California, then I’m worried.”
Dave Reid, director of the Santa Cruz County Office of Response, Recovery and Resilience, said in the context of historical records, it’s unfortunate to have this gap.
“I wouldn’t categorize it as a catastrophic loss, but it’s a bummer. We’ve lost this really cool continuity,” said Reid, who was a research scientist with the United States Geological Survey and has a background studying climate change. “It doesn’t mean we haven’t been collecting data, but this continuous record from the late 1800s is broken.”
Who volunteers?
Long-time Santa Cruz resident Ernest Hardy ran the co-op station near Highway 1 and Morrissey Avenue in his backyard from 2017 to 2022. He heard about the opportunity from an advertisement and wanted to learn more about climate, so he volunteered.
“Every day, at the exact same time, I was supposed to record the high temp, the low temp, and the rainfall … If there was rainfall, I did have to go out to a bucket with a measuring stick,” he said. “It was a pretty archaic system.”
In 2021, he noticed the temperature monitor said “error” rather than the temperature, so he reached out to his contact at the NWS multiple times, but never heard back. About a year later, Hardy said the NWS checked in when they noticed the missing data and told him that his original contact left the agency.
NWS retrieved the broken equipment.
“It was cool being a part of something that had such a legacy,” he said. “I felt the sting of breaking the trend that had been going on for 100 years.”
If the data could be automatically uploaded, Hardy said he would do it again.
Across Santa Cruz County, weather enthusiasts and education centers maintain personal weather stations that don’t typically follow the cooperative observer program requirements. But they still provide useful information and are still used for NWS forecasts.
Some of those volunteers are part of the NWS Citizen Weather Observer Program, including Live Oak resident Tom Ginsburg.
Ginsburg has had a weather station since early 2008, when he heard about it from fellow amateur radio operators.
“I’m just a geek about wanting to know what the weather is right here in our neighborhood,” he said.
Ginsburg has his temperature sensor and rain gauge on his asphalt roof. He knows it’s probably not always accurate because it’s exposed, but he and his neighbors enjoy having a fairly accurate and constantly updated station.
“I was never trying to be official. It’s just my neighbors and I caring about our weather,” he said. “It’s mostly just unofficial, daily weather.”
When he installed his station, he set it up so it automatically sends his data to the NWS, and Weather Underground, among others. He doesn’t have to manually send his data; it updates every few seconds of every day, automatically. Ginsburg uses a Davis Instruments Vantage Pro2 Plus station, which he purchased in 2019 for $950. Now, it costs more than $2,000.
His NWS data can be found on its website, at station CW9585, the number assigned to him by the Citizen Weather Observer Program.
He was surprised to hear about the weather service’s reliance on one climate station and wondered why it couldn’t come up with a daily average temperature for Santa Cruz last month, using data from local stations like his.
“I think it’s lame, honestly,” Ginsburg said. “It seems to me like that would be a no-brainer, very inexpensive for them to pull the data together.”
Do you want to become the next volunteer for the Cooperative Weather Observer Program Santa Cruz location?
For information, contact the NWS at w-mtr.webmaster@noaa.gov. For information about the program, visit https://www.weather.gov/box/coop.