California Warns 135-Day Summers and 40% Snowpack Loss by Midcentury
Updated
Updated · The New York Times · Oct 19
California Warns 135-Day Summers and 40% Snowpack Loss by Midcentury
2 articles · Updated · The New York Times · Oct 19
Summary
California’s Fifth Climate Change Assessment says the state faces major disruption within decades, with average temperatures projected to rise about 4°F by midcentury and 5 to 8°F by 2100.
Summer conditions are expected to last 135 days on average by midcentury, up from 90 days in 1981-2010, extending heat stress and raising risks for wildfires, tourism, agriculture and wildlife.
The report also projects a 40% decline in Sierra Nevada snowpack by midcentury, reducing a key source for reservoirs as more precipitation falls as rain and runs off quickly.
That shift would worsen both extremes—more severe droughts on one side and broader, more intense flooding on the other—while wildfire smoke exposure is expected to kill thousands more people each year.
Published Monday, the assessment portrays current warming in California as unprecedented against the past century and even estimates for the past millennium.
Since wildfire smoke is highly toxic, how will a 135-day summer permanently alter public health and childhood development in California?
With Sierra snowpack vanishing, can California's aging infrastructure capture enough winter rain to prevent a catastrophic groundwater collapse?
As extreme heat escalates, will new nature-based cooling strategies be enough to protect vulnerable communities from devastating climate disruptions?
From Snow Drought to Economic Shock: The Cascading Costs of California’s Accelerating Climate Extremes
Overview
This report shows how rising greenhouse gases have led to record-breaking warming in California and the West, causing more winter rain instead of snow and triggering rapid snowmelt. In 2026, a historic heat wave shrank snow cover by nearly half in just one month, setting new lows for snow water storage. As snowpack disappears earlier, darker ground absorbs more heat, which speeds up further melting and dries out soils. These changes ripple through the economy, increasing crop water deficits, reducing hydropower, raising insurance costs, and driving people to leave fire-damaged areas. Innovative water management strategies, like forecast-based reservoir operations, are helping communities adapt to these new climate realities.