January 2, 2026

Core Supply Dashboard

WY 2025-26 Precipitation Forecast: Above Normal, Decreasing to the South

Following an “average” year in 2024-25, it looks like much of California will have a chance of experiencing above average precipitation in water year 2025-26, with a modest drying gradient to the south. Refer to the Insights Section for more details (left sidebar).

The dashboard below shows the Core Supply status (Regions 2, 4, and 6, shaded blue) with observed data through December 31, 2025.

For details by region, see the Regional section below.

Core Supply:
CAP Forecast WY 2024-25

Core Supply:
Year-over-Year Comparison

Highlights

After a slow start, late-December storms delivered nearly 10 inches of precipitation to the Core Supply region, increasing water year progress by 19 percentage points.
December Core Supply precipitation totaled 9.73 inches — well above the climatological December average of 7 inches — and bringing the observed precipitation to 44.86% of water-year average.
This two-week surge in precipitation pushed the current water year past the early-season totals of analog years 2018–19 and 2024–25. See the Insights Section for more on this year’s precipitation.
Observed reservoir inflows through December 31, 2025 are available in the CRAFT section of the portal while the Insights section highlights Lake Shasta and Lake Oroville, comparing inflow forecasts alongside observed values.