Adaptation & Resilience

There has been a pronounced increase in the intensity, frequency, and duration of extreme heat events across California. In the Bay Area, average maximum temperatures have increased by 1.7°F (Ackerly et al. 2018). Air temperatures and extreme heat events are expected to continue to increase under all future emissions scenarios. Projections range between 4.4 and 5.8°F by mid-century to 5.6 and 8.8°F by late century (Ackerly et al. 2018).

Mean summer water stream temperatures have warmed by around 0.3°F since 1975 across the West (Isaak et al. 2017). Stream temperatures are projected to warm by 0.8 and 1.4°F by mid-century and 1.8 and 5.4°F by 2100 (Isaak et al. 2017).

Impact to Stanford

The frequency of extreme heat days (days above 92.7°F) is likely to increase from a historic baseline of five days a year to 13 days by mid-century and 23 days by 2100 (CalAdapt 2025). Extreme heat and higher rates of runoff will be experienced more acutely in areas of high impervious surface cover, such as main campus, faculty and staff housing, and Stanford Research Park. Extreme heat can lead to biodiversity loss because high temperatures may exceed a species thermal limits, reduce fecundity, increase disease pressure, eliminate habitat, or impact the resource base a species requires for survival.

To address these risks, Stanford is focusing on the following areas:

• Increased cooling demand, particularly in energy-intensive laboratory spaces
• Outside worker exposure to heat-related illnesses
• Stress on managed landscapes, including turf, vegetation, and trees
• Impacts to open space ecosystems, including habitat quality and biodiversity

The frequency of large fires across the Western U.S. has notably increased. There have been multiple wildfire smoke events on Stanford lands from fires originating elsewhere in California (2020) and Oregon (2023). Wildfire frequency, severity, intensity, and extent are projected to increase with the warmer and drier conditions lengthening the fire season across the Western U.S. (Westerling 2016).

Impact to Stanford

The number of days in a year in which wildfire conditions are high in and around Stanford is projected to increase from 16 days (historic) to 46–52 days by mid-century and 55–91 days by 2100 (CalAdapt 2025). Strong winds can accelerate the spread of wildfires and wildfire smoke, complicating fire suppression efforts and causing power outages. Increases in fire severity and frequency can result in biodiversity loss.

To address these risks, Stanford is focusing on the following areas:

• Lowered water quality from ash, debris, and post-fire runoff entering surface water sources
• Increased filtration and ventilation demands
• Risk of power disruptions that affect campus-wide operations and emergency response
• Damage to open space ecosystems, including habitat loss and degraded ecosystem function

California experiences several atmospheric rivers per year in late fall to winter months. Since 1980, these events have become 2–6% more frequent (Henny & Kim 2025). Bomb cyclones, which can generate extreme wind speeds, have occurred in the Bay Area recently, frequently in conjunction with atmospheric river events. Winter winds and westerly winds may become weaker with climate change, while summer winds may intensify (Wang et al. 2020). Atmospheric river events and storms with extreme rainfall are likely to increase in intensity and duration by 2050, with greater increases expected by 2100 (Dettinger 2011; Ackerly et al. 2018; Mak et al. 2023).

While average annual precipitation has remained mostly stable, with slight increases observed in northern California, winter precipitation rates have generally increased. Projections show slight increases in annual precipitation, with more significant increases during the winter months (Pierce et al. 2018; CalAdapt 2025). There is a high likelihood of more frequent and severe flooding by the late century due to more extreme rainfall events (Grantham et al. 2018).

Warmer temperatures have caused earlier snowmelt and earlier spring peak streamflows in California. Additionally, summer streamflows are projected to decrease, while winter peak flows are projected to increase (Grantham et al. 2018).

Impact to Stanford

Earlier snowmelt and runoff create high winter peak flows which, when accompanied by heavy rainfall events, can generate severe flood conditions, particularly in the 1% and 0.2% annual chance flood hazard areas. Portions of Jasper Ridge Biological Preserve, near Felt Lake, and along the San Francisquito Creek north-northwest of Sand Hill Road are in the 1% annual chance flood hazard zone (or 100-year floodplain) (the figure below). These areas are considered to have high risk of flooding, while areas in the 0.2% annual chance flood hazard zone (or the 500-year floodplain) have a moderate risk of flooding. Across the Bay Area, historic patterns of urban and suburban development and agricultural use within riparian areas have modified floodplains and compromised their ability to absorb the impacts of high flows.

To address these risks, Stanford is focusing on the following areas:

• Flooding and erosion damaging infrastructure, soils, and habitat systems
• Disruptions and delays to transportation corridors and deliveries
• Equipment and electrical system damage from water intrusion and wind damage
• Food storage reliability

Flood Hazard Areas within project boundary

Droughts have been observed over the last century throughout the West. Droughts in California have occurred twice as often between 1995 and 2014 as between 1896 and 1994 (Diffenbaugh et al. 2015). Droughts will very likely increase, particularly in the summer (Pierce et al. 2018). There is a high likelihood (80% chance) of a multidecadal drought in California by 2100 (Cook et al. 2015).

A 10% decline in April 1 snow water equivalent (SWE) was observed in Northern California between 1951 and 2010 (Micheli et al. 2018). April 1 SWE is the date at which snowpack reaches its peak and is a natural reservoir, and thus an indicator for water supply forecasts. As air temperatures continue to warm, reductions in snowpack are projected to accelerate. The April 1 SWE is projected to decline from 60% to 30% by 2050 and 11% by 2100 (Micheli et al. 2018).

Impact to Stanford

During extended drought, Stanford’s water supply is more dependent on constrained local sources, increasing pressure on already limited systems. Extreme drought can contribute to biodiversity loss in both terrestrial and aquatic environments.  At Stanford, where aquatic resources are already limited and impacted by suburban activity and development, aquatic species are particularly vulnerable. 

To address these risks, Stanford is focusing on the following areas:

• Increased reliance on limited local water sources
• Drier conditions elevating wildfire risk along fleet routes, near storage or staging areas, and near tenants and surrounding communities
• Reduced soil moisture impacting vegetation and long-term construction site performance
• Degradation of open space ecosystems, including habitat quality and carbon sequestration capacity