Bay Area Weather Observations Spark Debate on Climate Narrative

San Francisco, CA – A recent social media post by Bay Area resident Marc Joffe has ignited discussion regarding local weather patterns and the broader climate change narrative. Joffe challenged the concept of a "climate catastrophe," citing what he described as a summer of "generally below average" temperatures and early September rains that he believes brought an end to the wildfire season.

"No, Michael Mann, this Bay Area resident is not aware of your climate catastrophe. Temperatures this summer were generally below average and September rains are now bringing an early end to the wildfire season. Cherry picking the worst events is not scientific," Joffe stated on social media.

However, meteorological data for the region presents a more nuanced picture. While some areas experienced near-average precipitation, the National Oceanic and Atmospheric Administration (NOAA) reported that several Bay Area stations, including San Francisco International Airport (SFO) at 82% and San Jose International Airport (SJC) at 63%, recorded below-average precipitation for the water year ending September 30, 2025. Historical averages for September typically show minimal rainfall, with San Francisco averaging only 3mm (0.1 inches) and one rainy day.

Regarding temperatures, reports from late September 2025 indicated a significant heat surge across the Bay Area, with some locations experiencing temperatures in the 90s, and inland areas reaching the upper 90s and low 100s. This late-season heat was accompanied by a rising fire weather risk, suggesting that the summer was not uniformly below average and that the wildfire season's conclusion was not definitively early or solely due to September rains.

The tweet specifically referenced Michael Mann, a distinguished professor of atmospheric science and a prominent climate scientist known for his work on climate change, including the "hockey stick" graph. Mann is a vocal advocate for urgent action on climate change, often emphasizing the increasing frequency and intensity of extreme weather events as evidence of a warming planet. His work frequently highlights the long-term trends and global impacts of climate change, often contrasting with localized, short-term weather observations.

Scientists generally advise against drawing conclusions about long-term climate trends from isolated local weather events, emphasizing that climate refers to long-term averages and variability, while weather describes short-term atmospheric conditions. The Bay Area's climate is complex, influenced by its coastal proximity and varied topography, leading to microclimates where conditions can differ significantly across short distances.