Could we see triple digits by Mother’s Day?

You’ll definitely want to book an indoor brunch for Mom this year, because Mother’s Day looks HOT. However, before that heat arrives, our current heat will crash back down beginning Sunday. There’s a chance of a few showers Sunday night, and a near certainty of much cooler weather by Monday.

Saturday was a warm one. For the first time since March 20, Fresno hit 90! NAS Lemoore warmed to 94, Porterville 91, and Visalia joined the 90 degree club with a high of 90. Hanford was 89, Madera was 87, but Merced topped out at a much cooler 82.

As our next storm approaches the coast, temperatures will begin to cool down. Look for highs on Sunday to warm to only around 80. Clouds will begin to move in by the afternoon, and there is a chance of a few showers Sunday night. Monday will be mostly cloudy and cooler still, with highs only in the low 70’s, and that chance of a shower continuing. Tuesday will look a lot like Monday.

In the Sierra Nevada, showers should develop Sunday afternoon, and continue off and on through Tuesday. The snow level should remain above 7000′

The sun will come out… Wednesday, and that’s when our next warm up begins. We’ll warm up close to 80 by Wednesday, near 90 by Thursday, then stay in the low 90’s for a few days. Our first real chance at triple digits this year arrives (sorry moms) on Mother’s Day.

As we heat up next week, we can expect our air quality to decline: sunny, hot weather aids in ground level ozone formation.

Both the American Lung Association and the San Joaquin Valley Air Pollution Control District released their annual reports recently, and while there is some good news about recent progress being made, the overall message is that our air quality stinks. Clean air is vital for good health; long term exposure to bad air quality can intensify asthma, COPD, flu, pneumonia, heart disease, hypertension, and rheumatic fever, especially in those over 65. However, our bad air quality in the Valley isn’t totally our fault – we get contributions from both near and far. Let’s take a look at the reports.

Let’s start with the good news. In the 2025 Annual Report to the Community from the San Joaquin Valley Air Pollution Control District, they acknowledge that our air quality isn’t the best… but it’s come a long way in the past 20 years. Even though the population in the Valley continues to grow, even though there are more cars on the road than ever before, our air quality continues to improve. That’s because of the strict regulations and guidelines they put into place decades ago, which have helped air quality in the Valley steadily get better.

However… it still has a LONG ways to go before it could ever be considered ‘healthy’, and that’s what the American Lung Association’s 2026 State of the Air report looks at. This report concentrates on two main pollutants: Ozone and Particulate Matter.

Ozone is a type of oxygen. The kind we breathe and are most familiar with is O2. Ozone has an extra Oxygen molecule, making it O3, which is highly reactive: it essentially wants to burn our lungs. Most of the Ozone in our atmosphere is located in the Stratosphere, about 8 to 10 miles above the surface of the Earth. This is the “good” ozone, which acts to absorb UVC and some UVB radiation from the Sun. While too much UVB radiation can give us a sunburn, UVC radiation is lethal for most living things… so it’s a very good thing that Stratospheric ozone absorbs all of it. A hole in this Ozone layer developed over Antarctica in the 1990’s, which was caused by Chlorofluorocarbons (CFC’s) . in the atmosphere… those were used as a propellant in spray cans (like hair spray). After CFC’s were banned, the Ozone layer slowly repaired itself, and it’s good again now. The 10% of Ozone that is not in the Stratosphere is down here at the surface, and that’s the bad kind. Long term exposure to this Ozone can lead to permanent lung damage, chronic respiratory diseases like asthma or COPD, cardiovascular stress (which can lead to heart attacks or stokes), and stunt lung growth in children. And we have a significant Ozone problem in the San Joaquin Valley: out of over 200 cities in the United States, Visalia has the 2nd worst rate of Ozone pollution, while Fresno has the 5th worst. Wow.

The other pollutant the State of the Air report talks about is Particulate Matter (PM), which is very small, fine particles of soot, dust, smoke, or anything, really. The problem with them is their size: 2.5 microns or less, small enough to bypass our natural defenses (nose hair, eyelashes, etc.), and enter the body. Once inside, they can lodge themselves in our lungs, and start to damage them, which can reduce lung function and aggravate asthma. These small particles can also enter the bloodstream… and if they happen to be mercury, or lead, or cadmium, they can become toxins to your internal organs. We also have a very significant PM problem in the San Joaquin Valley: Bakersfield is the most (#1) polluted city in the nation with respect to Particulate Matter, while Fresno is the 4th worst, and Visalia is the 5th worst. Again, this is out of over 200 ranked cities.

Now, this isn’t totally our fault. We don’t emit that much more pollution than everyone else… we just happen to live in an area that traps other cities pollutants. First, we actually get somewhat significant air pollution all the way from China! Back in 2010, about 25% of our air pollution originated in China, and made the loong journey across the Pacific to California. However things have changed recently: Around 2013, China got serious about air pollution. They implemented strong rules and restrictions that were designed to reduce their air pollution. And you know what? It’s working! Air pollution in China has dropped around 40% in the past 15 years, which means for us, their contribution to our bad air quality has dropped from 25% to around 15%.

But the main contributors to our bad air quality are our surrounding geography, and local weather patterns. The San Joaquin Valley is surrounded by mountains. The airflow across the United States is generally from west to east, and to our east are the tallest mountains in the lower 48 states! The Sierra Nevada, Tehachapis, and Coast Range block pollutants from leaving the Valley very effectively. Our weather patterns are our other big problem. When upper high pressure sets up over California, not only does it block incoming storms, it pushes air down to the surface… effectively putting a ‘lid’ on the atmosphere. With the mountains blocking any horizontal escape… incoming pollutants have no escape.

Incoming pollutants? Yup. We deal with our air pollution, and other cities’ air pollution, too! If you look at the city rankings of worst air quality, you see the usual suspects: Los Angeles, Houston, etc. But not San Francisco. Generally speaking, for a major city, their air quality is decent. The whole Bay Area is almost similar in size to Los Angeles, yet LA’s smog is famous… but you rarely hear about terrible air quality in San Francisco. Why?

Los Angeles is similar to us, surrounded by mountains, with little escape possible for the pollutants. San Francisco doesn’t really have ‘mountains’… more like big hills. And, more importantly, SF has an escape route for the pollution! To the east of the City is the Sacramento-San Joaquin river delta, where those two rivers drain the Valley into San Francisco Bay… which provides a nice sea level escape for the Bay Area’s bad air. Our dominant wind direction in the San Joaquin Valley is from the north west. So, significant air pollution from San Francisco is pushed inland, then rides that northwest wind down the Valley, right to Fresno, Visalia, Hanford, and Bakersfield. Combine that with the air pollution we do create, and it’s a recipe for very bad air quality!

So, what’s ahead for our future? While the San Joaquin Valley Air Pollution Control District is doing a great job in improving our air quality, recent decisions on the Federal level are not. The Environmental Protection Agency (EPA) has recently relaxed many controls on air quality, which will eventually lead to our air quality worsening yet again. The more research that is done on Particulate Matter and the bad effects it can cause in our bloodstream and lungs, the more obvious it’s becoming that this is something that really needs to be restricted, so the EPA did just that in 2024. However, those restrictions were recently tossed aside. The EPA had also just set limits on how much Mercury and other air toxins could be released from coal fired power plants. Mercury is especially dangerous to babies, and has been noted in Yosemite National Park. But again, the EPA eliminated those new restrictions just recently. The EPA had just set new requirements for the turbines in gas fired power plants, which would clean up Ozone forming emissions. But again, those were recently repealed. In 2023, the EPA set new rules to limit Methane emissions from new and existing oil and gas wells. There are plenty of oil wells around Coalinga, down to Kern County. The EPA has just delayed the compliance requirement with those rules again. Other power plants and industrial sites that may had been having issues in staying compliant with pollution regulations? All you have to do now is email the EPA, and they’ll grant you a waiver.