As we transition from WY 2024–25 to 2025–26, here’s a quick peek at how we add value during the water year. Subscribers get reports like this after significant storms. If you’d like this information in your inbox all year, it’s included with a subscription to our California Annual Precipitation (CAP) forecast. 

Between October 13–14, 2025, California saw a compact early-season storm that delivered meaningful precipitation to several basins, especially the southern San Joaquin, Tulare, and Kern and Kings areas. It provided a modest, early lift to water-year (WY) totals. 

Event Analysis

We assess the impact of the Oct 13–14 event using near real-time National Weather Service data. As with prior ad-hoc reports, this dataset represents only a subset of the stations used in our monthly verification. It’s best suited for approximating event impact rather than providing precise WY totals. Figures should be treated as preliminary and offer a rough estimate of the storm’s influence.

• Core Supply Regions: The October 13-14 event added roughly 9 percentage points to the total WY precipitation accumulation. 
• Statewide: The state as a whole gained 7.42 percentage points from October 13-14.  

We can discern regional patterns in a relative sense, but the percentages should not be taken as precise measures of precipitation received.  Keeping this in mind: 

Regional Highlights: 

In descending order of impact: 

• Region 6 – Kern & Kings (KTKK): + 13.95% Biggest accumulation bump; Bakersfield’s WY precipitation total climbed nearly 14% with this event.
• Region 4 – San Joaquin & Tulare (SJ-T): +12.02% Hanford recorded the largest gain with 13.9% increase.  
• Region 5 – Central Coast (CENT): +9.01% Paso Robles recorded an increase of 11.03 percentage points. 
• Region 3 – San Francisco Bay (RNSF): +5.81% San Jose up 11.28 percentage points; Santa Rosa up only 3.61 pts, pulling the regional average down. 
• Regions 2 (SYFA) and 7 (SCAL, MJVE): Recorded minimal precipitation (less than 4% gain) on the fringes of this storm.

This breakdown highlights the variability in storm impact across the state, with Regions 4-6 seeing the most significant accumulation. 

Visual Analysis

The images below, from California Water Watch, show water-year-to-date precipitation estimates as a percentage of average. 

The left image captures conditions prior to the precipitation event (through October 12, 2025), while the right image shows conditions following its conclusion (October 15, 2025). Overlaid on these images are the approximate boundaries of the CAP regions, providing a view of the spatial distribution of precipitation. 

From Oct 12 to 15, the clearest color shifts are in the southern half of the state. Regions 4, 5, and 6 move from an array of accumulations (0 to >200%) toward almost fully purple (>200%). Portions of Region 7 surged from 0-20% WY precipitation to >200%. Regions 1–3 show modest changes, however it is important to note: large portions of Regions 1–4 were already >200% of normal before the event, so additional gains are not captured when the legend tops out, masking new accumulation.

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