The 2025 L.A. wildfires rank as the 10th-costliest weather disaster in U.S. (and world) history, using inflation-adjusted data from 1980-2025 from Climate Central, based on foundational work from NOAA.

A brief cooldown is on tap, and perhaps some legitimate midwinter weather by late Jan—but for now, most of the southwest 2/3 of the United States is still eerily non-wintry. @climateconnections.bsky.social yaleclimateconnections.org/2026/01/stil...

The institutional memory of NOAA has suffered: “All these leaders of things who’ve been around for a long time and know how it operates, we’re kind of moving on.” NOAA lost 2,000 of its 11,800 employees through layoffs and retirements since Trump took office”. Now at its lowest staffing level ever.

Today's king tide peaked in Santa Barbara, CA, at 2.29’ above MHHW, the highest water level since records began in 1973 (old record: 2.23', 12/13/2012).Their 3rd-highest water level on record was during yesterday's high tide (2.19'). According to NOAA, the 2026 record is about a 1-in-100-year event.

Today's king tide peaked in San Francisco at 2.56’ above MHHW, the 3rd-highest water level since records began in 1897. Only two water levels in 1983 were higher. According to NOAA, the 2026 level would have been a 1-in-100-year water level 30 years ago, but is now more like a 1-in-70-year event.

A 4th study not included in the Grist article found that in the 90 days after January's fires in LA emergency medical encounters increased by 24% for acute pulmonary illness, 46% for myocardial infarction (heart attacks), and 118% for blood chemistry abnormalities. www.jacc.org/doi/10.1016/...

3 studies: 1) January’s infernos in Los Angeles killed >440 once you factor in the smoke (official toll: 30). 2) Wildfire smoke kills 40,000 Americans a year, which could increase to 71,000 by 2050. 3) Canada’s wildfires in 2023 significantly worsened childhood asthma across the border in Vermont.

I highly recommend the 2023 book, "California Against the Sea: Visions for Our Vanishing Coastline", by LA Times environmental reporter Rosanna Xia, on sea level rise issues for California. There's a great discussion about how hard it is politically to do managed retreat from doomed coasts.

At Toronto Pearson Airport, a dedicated team from Falcon Environmental uses a unique approach to keep the skies clear, featuring their star employee, Ivan the bald eagle. The Weather Network's Mark Robinson spoke to the experts about how they use falconry to protect both passengers and wildlife.

From high-impact weather events to stratus clouds dancing over the open ocean, this year was filled with impressive satellite imagery. We look back on the most compelling satellite views of 2025. 1) Mesovortices slosh within Hurricane Melissa’s ferocious eye (October 8).

Got to do multiple meteorologist meet-ups during my week-long Atlanta vacation! The first was with @climateguyw.bsky.social, who gifted me this awesome Hurricane Hugo photo. Turns out both of us had harrowing experiences in the eye—mine in air, and Guy’s on the ground (in Charleston).

21’ waves are forecast on Lake Superior tomorrow. The largest waves ever recorded on the Great Lakes were 28.8’, measured in Lake Superior between Marquette and Munising on Oct. 24, 2017. Buoy coverage isn’t good this time of year, though.

There's an interesting special section in the NYT today on the future of NYC, including the climate risks. www.nytimes.com/interactive/... Notable is this graph of local changes in extreme rainfall:

A meeting of the meteorologists! Great to meet up with @michaelrlowry.bsky.social and Kait Parker and kids, with my family, at the Atlanta Zoo today. Crazy record warm temps in the 70s for the 5th straight day for our vacation here.

My latest post is also on this topic: yaleclimateconnections.org/2025/12/impr... It’s super important to know if you are breathing good air indoors, and there are many cost-effective ways to monitor and improve your air quality.

🚨🔥 Warmest Christmas on record for the Contiguous U.S.! The average high of 57.9F and the average low of 36.6F each broke the Christmas record by a full 3F. 🔥🚨

Fix indoor air pollution and poor ventilation! I often measure CO2 of 2,500 ppm due to poor ventilation in buildings and airplanes. At this level, COVID spreads easily, and brains suffer: test scores can drop 44%. Suggestions: invest in HEPA filtration, ditch your gas stove, improve ventilation.

Smart: RI has a statewide document prioritizing 10,000 crucial assets—infrastructure, healthcare facilities, emergency service—for adaptation funding. Bond proceeds will finance a state revolving loan fund for multi-million-dollar resilience projects; grants will fund smaller design efforts.

A September brookings.edu report, “Who Bears the Burden of Climate Inaction?”, found climate -driven changes in home insurance premiums, home energy costs, and smoke effects on mortality are $400-$900 per household per year, with much higher costs—upward of $1,300 a year—in the hardest-hit places.

"Not since the ransacking of the Library of Alexandria have we witnessed such a wanton, intentional assault on scientific knowledge."

There is no way to stop climate change research at NCAR without doing irreparable damage to weather research. "The idea that you can just pull “vital” weather research activities out of a unique, vibrant scientific environment and expect that they will just continue to roll along is ludicrous."

@bhensonweather.bsky.social spent most of his career working at NCAR. He writes, "Working at NCAR and UCAR was an enormous privilege and one of the great joys of my life. I gained a humbling appreciation for the intricacy of the atmosphere." yaleclimateconnections.org/2025/12/trum...

It's like on the eve of WWII we decided to stop funding R&D into weapons systems to develop advanced aircraft, ships, and tanks. Climate change is going to kick our butts if we lose NCAR (and NOAA) at a time when climate change is increasing extreme weather events capable of crashing the economy.

These people are nuts. NCAR developed the GPS dropsonde, which revolutionized the understanding of TC structure, improved forecasts, and validated remote sensing platforms, as documented in over 400 peer-reviewed publications in the last 25 years. And that’s just one of NCAR’s countless advances.

A crazy event in the report: “Following the retreat of South Sawyer Glacier, a landslide in southeast Alaska’s Tracy Arm in August 2025 generated a tsunami that swept across the narrow fjord and ran nearly 1,600 feet up the other side. Fortunately, the fjord was empty of cruise ships.”

It’s been observed that tropical cyclones have been migrating poleward in recent years, and climate change was suspected as a cause. But this study found SST patterns caused it, “and that future changes may differ markedly from the recent multi-decadal trends.” www.nature.com/articles/s41...

A positive note: The 1980s Coastal Barrier Resources Act made “3.8 million acres of barrier islands ineligible for federal flood insurance, discouraging development. Studies since show that has saved taxpayers close to a billion dollars a year.” Read more at: www.miamiherald.com/news/local/e...

@michaelwara.bsky.social says: “The only solutions are going to involve really intensive engineering. There’s going to be places where Marin County has the money to defend and places where it’s not going to be able to defend.” Cost: up to $1.9 billion for San Rafael (pop. 60,000).

For the sixth time in sixth months, global temps have come in just behind the record-smashing pace of 2023 + 2024. And that's w/La Niña conditions in place, which tend to bring down global temps slightly. An update from @drjeffmasters.bsky.social: yaleclimateconnections.org/2025/12/3rd-...

Monitor your indoor PM 2.5 levels to understand your filtration and ventilation needs. The South Coast AQMD tests how well the most popular home monitoring devices perform compared to expensive official units: www.aqmd.gov/aq-spec/sens.... And this site has some super-detailed reviews:

From anisota.net/harvest, my most-used words in 2025 were: 1. "hurricane" (87×) 2. "climate" (81×) 3. "weather" (52×) 4. "storm" (43×) 5. "record" (40×) Cool tool to analyze your Bluesky posts, thanks @kellyhereid.bsky.social!

The Miami Herald tracked 16,569 flood complaints from over 12,000 locations in Miami-Dade and Broward over the last 11 years, and found 32% were outside the newly-expanded 500-year flood zones scheduled to go into effect as early as 2026: www.miamiherald.com/news/local/e...

Are you one of the 38% of U.S. households with a gas or propane stove? If so, spend the $50 needed to get an induction stove! New study: "if you use a gas stove, you’re often breathing as much nitrogen dioxide pollution indoors from your stove as you are from all outdoor sources combined.”

Great overview of CO2 monitoring. High CO2 is associated with COVID spread, and causes sleepiness, headaches, fatigue, and lower test scores (15% drop at 1000 ppm; 44% drop at 2500 ppm). I’ve found 2000-3000 ppm in restaurants, doctor offices, meeting rooms, churches, and airplanes.

4) But it's not just warm sea - you still need some level of mid-level humidity and limited shear for RI (looking at it very simply) - and the area and temporal frequency of these 3 conditions co-existing is increasing; 2025 was no different, especially over the Caribbean (Melissa, anyone?)

Aviation accidents “receive an intense investigation by the NTSB with specific recommendations to improve safety, while events like the July 4th flash flood with 119 fatalities rely on entities like Camp Mystic self-policing themselves and developing their own plans to try to improve safety.”

It’s critical to make “climate‑aware, nationally consistent mapping information public. Our flood mapping program should be treated as critical national infrastructure, as important as the core weather forecasting that the National Weather Service provides.” Cost: $3-$12 billion.

On Giving Tuesday, there's no better climate cause than @csldf.org, the Climate Science Legal Defense Fund, csldf.org. They provide free legal and educational support to researchers facing harassment and intimidation, and have been record busy this year. I'm a founding board member.

Great podcast! Everyone should be breathing healthier indoor air.

Gift idea for those concerned about wildfire smoke and COVID: An excellent HEPA unit that I’ve researched (and own), the Coway Airmega AP-1512-HH “mighty”, is on sale today for $153 on Amazon. A home-built Corsi-Rosenthal box is better and costs just $100 (but is louder and takes up a lot of space).

Scientific information does not flow into policy the way most scientists think. Twenty years after her jarring first day as a fisheries-biologist-turned-Senate-staffer, @sheril.bsky.social lays out what every scientist hoping to influence policy on the Hill needs to know: issues.org/information-...

After 9 straight years with a landfalling hurricane—and a record 5 straight (2020-2024) with a major hurricane landfall—the U.S. escaped any hurricane landfalls in 2025. With the unprecedented disarray affecting FEMA and NOAA, we were extremely fortunate not to be tested by a major hurricane!

Deadliest tropical cyclone of 2025: A rare low-latitude tropical storm (Senyar, which formed at 3.7N) contributed to flooding in Indonesia, Thailand, and Malaysia that has killed 775+ and left 430+ missing. Lhokseumawe, Indonesia had 15.12" (384 mm) of rain in 24h ending 12Z Nov. 26.

Great summary of the season.

Behold what happens when you fix Roger Pielke Jr's serial errors:

Another great read from @scrawford.bsky.social: "We can’t rely on the insurance industry to be the only risk-signaler for homes. These companies may be tracking hurricanes and wildfires, and translating those risks into higher premiums, but they are likely to exclude saltwater intrusion coverage."

Drought is climate change's greatest threat. An attribution study by www.worldweatherattribution.org found this year's Iran drought was a 1-in-10-year event; this would have been a 1-in-50 to 1-in-100-year event without human-caused climate change. President of Iran says they will move the capital.

My post today is a reminder that we need to spend a ton of money on adaptation for our new climate, based on a report issued in March on U.S. infrastructure needs. yaleclimateconnections.org/2025/11/u-s-...

Interesting. Synthetic hurricane modeling showing higher % of named storms hitting the U.S. as hurricanes the past 22 years vs. prior 22 years. "One theory: warming seas are making storms stay longer at hurricane strength. This may not necessarily be evident from the historical data that we have."

During the core months of hurricane season (Aug-Sep-Oct), fairly persistent anomalous "troughiness" was centered over the southeast U.S., which resulted in anomalous counter-clockwise steering flow around it. This helps explain why hurricanes generally turned northward well before reaching the U.S.