The Brief

We all know it’s hot — and getting hotter.

According to NOAA and NASA, the 10 warmest years globally since 1850 have all occurred in the past decade. In less than 200 years, when the Industrial Revolution began, the global average temperature has increased by more than two degrees Fahrenheit.

While the planet’s climate has changed dramatically over millions of years, atmospheric carbon dioxide levels are now at their highest in millenia due to pollution from human society. Scientific consensus proves the modern, rapid weather shifts we're now experiencing are a result of how we humans, largely through fossil fuel pollution, are changing the climate.

The science is clear that we’re entering a new era of extreme heat. We’re unlikely to keep global temperatures below the threshold scientists have raised the alarm about for years, and weather extremes will only become more frequent and intense if we don’t dramatically cut emissions in the next seven years or soon after.

So, as the earth heats up, what is “normal” vs “extreme” heat? How is the climate crisis affecting heat here in Southern California?

Normal heat in the Southland

Of course, July through September and even much of October in southern California, it's normal for the weather to heat up. Southern California has deserts, mountains and the ocean, so our temperatures vary widely. From geography to tree cover to local weather patterns, there are a lot of factors that naturally make some parts of Southern California hotter than others. My colleague, science reporter Jacob Margolis, explains in more detail in this story.

'Extreme' vs 'normal' heat

What’s normal versus extreme depends on where you live — after all, what’s considered a hot day in Santa Monica is a far cry from a hot day in Palm Springs.

The climate crisis is shifting average temperatures hotter — not every day, or every season, but it’s driving an average increase in both day and nighttime temperatures.

How the climate crisis is expected to affect heat in California.

(

Courtesy of the California Legislative Analyst's Office

)

That also means longer and more frequent “heat waves,” during which temperatures reach higher extremes and stay there for longer periods of time. A week-long heat wave in early September 2022 was the hottest and longest in the state’s record for that month, which is already one of the hottest months in California.

“Whether you're on the coast, whether you're in the mountains, whether you're in the deserts, whether you're in between, all those averages are going up,” said Alex Tardy, a meteorologist with the National Weather Service (NWS) San Diego office.

In Southern California, the most rapid and dramatic increases are happening in the deserts and the mountains, already extreme environments, Tardy said.

Doing the math

Since 1901, the National Oceanic and Atmospheric Administration (NOAA) has collected temperature records from weather stations across the country. They use that information, combined with other data and computer models to calculate specific “climate normals” for different regions.

The “normals” add up to a 30-year average temperature, or what’s considered a long-term average temperature. NOAA’s National Weather Service uses those average temperatures to decide whether a heat event is extreme or not.

“Abnormal heat is typically daytime temperatures 10 to as much as 20 degrees Fahrenheit warmer than the long-term average,” said Tardy. “When we talk about a heat wave, what we're talking about is really two or more days when temperatures are much above average.”

NOAA's latest climate normals map showing the normals from 1991-2020 minus 1981-2010 normals. Most of the U.S. shows significant warming, especially in the West, Southwest and East, where soem normals jumped by a whole degree already.

(

Courtesy of NOAA

)

Since our bodies take time to acclimate to changes in temperature, those averages depend on the time of year. For example, Tardy said that an abnormal threshold in mid-July in L.A would be 90 degrees, whereas it would be 110 degrees in Palm Springs.

“We look at the heat risk, we look at the departure from normal, we look at the ability for someone to be able to acclimate to the heat,” Tardy said. “We don't just look at the fact that it's a hundred degrees and that requires a heat warning.”

Every 10 years, NOAA recalculates the climate normals — most recently in 2020 — and overall, averages are going up.

“Normals and averages — it's always been a moving target, but the target is moving up and up and up and warmer and warmer and that's what we've seen the past 10 years,” said Tardy.

Six of the last 10 years have been the hottest on record in Southern California, Tardy said.

Ranking heat waves like hurricanes 

When the NWS sees abnormal temperatures in the forecast, that can spark a heat watch or excessive heat warning or advisory. These warnings are meant to help individuals stay safe, inform governments and businesses, and can trigger some legal protections for outdoor workers.

NWS is currently prototyping an extreme heat risk scale that will more directly communicate how different heat extremes translate to health risk. They've already used it in tweets about the current heat wave:

Tardy said improving early communication about the dangers of heat is especially important as the climate crisis makes heat more extreme and frequent — already, heat kills more people than any other weather event in the U.S.

“Heat is a very silent killer,” Tardy said. “It's not something that we see like a hurricane or a flood or a winter storm. It's something that just kind of catches up to you over time. It's one of those things that a lot of people don't take seriously until it happens to them.”

The idea is to rank heat waves similar to how we rank hurricanes. California lawmakers also passed a bill in 2022 requiring a statewide heat wave ranking system by 2025.

The prototype scale for ranking heat waves amid a changing climate.

(

Courtesy of NOAA

)

“People can really relate to the magnitude or the potential impact on a five versus a one [for a hurricane],” Tardy said. “So we're trying to do that also with heat.”

NOAA’s current prototype, which you can peruse here, uses a color scale to indicate how dangerous forecasted temperatures may be to health. NWS is currently using it to inform its official heat alerts, but it will likely be a few years before it’s used in widespread public communication.

“The overall magnitude of the event — not just, 'It's 110 degrees' — that's something we're really trying to focus on more,” Tardy said.

The scale forecasts seven days in advance and allows a more nuanced view of heat as it relates to health by incorporating data about:

• How significantly above normal the temperatures are at your location.
• The time of the year. 
• How long the unusual heat will last (will overnight temperatures get low enough to lower heat stress? How much warmer than average will those temperatures be?)

Weather forecasting has gotten a lot better, and it is another tool to save lives amid the climate crisis, Tardy said. He hopes the heat risk scale will better communicate the health dangers of heat and help people better protect themselves and their loved ones amid our hotter normal.

“We have to do a better job ingraining it into the culture — that it's not just hot all the time, it's not just hot because it's summer,” Tardy said. “When we start talking about heat alerts or heat warnings, it's something that should be treated as, ‘Hey, this is very unusual.’ And we can't just treat the day or the activity as normal.”

Staying safe in the heat

The Trump administration says it’s planning to freeze about $10 billion in federal support for needy families in California and four other Democrat-run states, as the president announced an investigation into unspecified fraud in California.

The plans come on the heels of the Trump administration announcing a freeze on all federal payments for child care in Minnesota, citing fraud allegations against daycare centers in the state.

The state’s Democrat governor, Tim Walz — who ran for vice president against Donald Trump’s ticket in 2024 — announced Monday he was dropping out of running for reelection. He pointed to fraud against the state, saying it’s a real issue while alleging Trump and his allies were “seeking to take advantage of the crisis.”

On Monday, the New York Post reported that the administration was expanding the funding freeze to include California and three other Democrat-led states, in addition to Minnesota. Unnamed federal officials cited “concerns that the benefits were fraudulently funneled to non-citizens,” The Post reported.

Early Tuesday, President Trump alleged that corruption in California is worse than Minnesota and announced an investigation.

“California, under Governor Gavin Newscum, is more corrupt than Minnesota, if that’s possible??? The Fraud Investigation of California has begun. Thank you for your attention to this matter! PRESIDENT DONALD J. TRUMP,” the president wrote on his social media platform Truth Social.

He did not specify what alleged fraud was being examined in the Golden State.

LAist has reached out to the White House to ask what the president’s fraud concerns are in California and to request an interview with the president.

“For too long, Democrat-led states and governors have been complicit in allowing massive amounts of fraud to occur under their watch,” said an emailed statement from Andrew Nixon, a spokesperson for U.S. Department of Health and Human Services, which administers the federal childcare funds.

“Under the Trump administration, we are ensuring that federal taxpayer dollars are being used for legitimate purposes. We will ensure these states are following the law and protecting hard-earned taxpayer money.”

Gov. Gavin Newsom’s press office disputed Trump’s claim on social media, arguing that since taking office, the governor has blocked $125 billion in fraud and arrested “criminal parasites leaching off of taxpayers.”

Criminal fraud cases in CA appear to be rare for this program

Defrauding federally funded programs is a crime — and one LAist has investigated, leading to one of the largest such criminal cases in recent years against a California elected official, which surrounded meal funds.

When it comes to the federal childcare funds that are being frozen, the dollar amount of fraud alleged in criminal cases appears to be a tiny fraction of the overall program’s spending in California.

A search of thousands of news releases by all four federal prosecutor offices in California, going back more than a decade, found a total of one criminal case where the press releases referenced childcare benefits.

That case, brought in 2023, alleged four men stole $3.7 million in federal childcare benefits through fraudulent requests to a San Diego organization that distributed the funds. All four pleaded guilty, with one defendant sentenced to 27 months in prison and others sentenced to other terms, according to authorities.

It appears to be equivalent to one one-hundredth of 1% of all the childcare funding California has received over the past decade-plus covered by the prosecution press release search.

Potential impact on California families

The plans call for California, Minnesota, New York, Illinois and Colorado to lose about $7 billion in cash assistance for households with children, almost $2.4 billion to care for children of working parents, and about $870 million for social services grants that mostly benefit children at risk, according to unnamed federal officials speaking to the New York Times and New York Post.

In the largest category of funding, California receives $3.7 billion per year. The program is known as Temporary Assistance for Needy Families, or TANF.

 ”It's very clear that a freeze of those funds would be very damaging to the children, families, and providers of California,” said Stacy Lee, who oversees early childhood initiatives "at Children Now, an advocacy group for children in California.

 ”It is a significant portion of our funds and will impact families and children and providers across the whole state,” she added. “It would be devastating, in no uncertain terms.”

About 270,000 people are served by the TANF program in L.A. County — about 200,000 of whom are children, according to the county Department of Public Social Services.

“Any pause in funding for their cash benefits – which average $1000/month - would be devastating to these families,” said DPSS chief of staff Nick Ippolito.

Ippolito said the department has a robust fraud prevention and 170-person investigations team, and takes allegations “very seriously.”

It remains to be seen whether the funding freeze will end up in court. The state, as well as major cities and counties in California, has sued to ask judges to halt funding freezes or new requirements placed by the Trump administration. L.A. city officials say they’ve had success with that, including shielding more than $600 million in federal grant funding to the city last year.

A union representing California childcare workers said the funding freeze would harm low-income families.

“These threats need to be called out for what they are: direct threats on working families of all backgrounds who rely on access to quality, affordable child care in their communities to go to work every day supporting, and growing our economy,” said Max Arias, chairperson for the Child Care Providers United, which says it represents more than 70,000 child care workers across the state who care for kids in their homes.

“Funding freezes, even when intended to be temporary, will be devastating — resulting in families losing access to care and working parents facing the devastating choice of keeping their children safe or paying their bills.”

Federal officials planned to send letters to the affected states Monday about the planned funding pauses, the New York Post reported. As of 3 p.m. Tuesday, state officials said they haven’t gotten any official notification of the funding freeze plans.

“The California Department of Social Services administers child care programs that help working families afford safe, reliable care for their children — so parents can go to work, support their families, and contribute to their communities,” said a statement from California Department of Social Services spokesperson Jason Montiel.

“These funds are critical for working families across California. We take fraud seriously, and CDSS has received no information from the federal government indicating any freeze, pause, or suspension of federal child care funding.”

Housing officials in the city of Los Angeles say a pandemic-era voucher program is set to run out of money later this year, putting thousands of renters at risk of homelessness.

The federal Emergency Housing Voucher program was launched in 2021 as a way to get vulnerable people off the streets and into housing during the COVID-19 crisis. The city of L.A. received more than 3,300 of the vouchers.

With federal funding now running out, the city is preparing to wind down the program. On Monday the city’s housing authority said it had told 2,760 tenant households and 1,700 landlords that unless new funding is found, vouchers will expire by November or December of this year.

“We are providing this notice nearly a year in advance because our families deserve the respect of time to prepare, but this is not a notice of resignation,” said L.A. Housing Authority President Lourdes Castro Ramírez said in a news release. “We are exhausting every avenue — at the local, state and federal levels — to bridge this funding gap.”

The Housing Authority said each household using a voucher had an average of 1.58 members. That puts more than 4,000 Angelenos at risk of losing their housing later this year.

Homelessness progress could be reversed

Congress originally intended the program to continue through 2030, but last year, the Trump administration announced funding would end sooner. The program’s demise risks reversing L.A.’s reported progress at stemming the rise of homelessness.

After years of steady increases, the city has registered slight reductions in the number of people experiencing homelessness for the past two years. In 2023, the region’s homeless services authority reported 46,260 people experiencing homelessness in the city of L.A. By 2025, that number had fallen to 43,695.

The accuracy of those official counts has been questioned by local researchers, but elected officials have cheered the numbers as a sign that the tide is turning in addressing one of L.A.’s most vexing problems.

With thousands of renters now at risk of losing a key resource helping them afford the city’s high rents, sharp increases in homelessness could be on the horizon, said Mike Feuer, a senior policy advisor with the Inner City Law Center.

“They're going to fall into homelessness, and they're going to increase L.A.'s homeless population by almost 10%,” Feuer said. “Those are the implications of what the Trump administration is doing.”

Voucher holders have low incomes; many have kids

According to L.A.’s Housing Authority, about 1-in-4 voucher holders has children and 1-in-5 is elderly. And about 40% are disabled. These households have an average income of less than $14,000 per year, and they receive an average of $1,789 per month in rental subsidy while paying about $350 out of their own pockets.

The loss of federal funding for Emergency Housing Vouchers is distinct from the issues facing renters using Housing Choice Vouchers, another federally funded program often referred to as Section 8. Existing vouchers in the Section 8 program have continued to be funded, but federal funding reductions have caused city officials to cut the amount of rent new vouchers in that program can cover by 10%.

L.A. Housing Authority officials said they have dedicated staff reaching out to tenants to explore other housing resources that might keep them housed after the vouchers expire.

Manuel Villagomez, an attorney with the Legal Aid Foundation of Los Angeles specializing in subsidized housing, said with city and state budgets strapped, tenant advocates are not counting on California to find alternative funding sources to continue the program.

“It seems like it's a tragedy in the making,” Villagomez said. “We're preparing for the worst.”