Welcome to California Water Watch! This site offers the most current local and statewide water conditions down to your region and even your neighborhood.
This information is updated dynamically from a variety of data sources. Everyone is welcome to research, learn, and stay
informed about California's most precious resource -- water.
Snapshot of California Hydroclimate and Water Supply Conditions
California has a Mediterranean climate characterized by warm, dry summers and mild, wet winters. The climate can vary depending on the geographical region
where you live, and climate change is increasing this variability.
The maps below show current statewide hydroclimate and water supply conditions, including precipitation, temperature, reservoir storage, groundwater
conditions, snowpack, streamflow, soil moisture and vegetation conditions.
To view the conditions in your local area, enter your address or zip code in the location finder.
California’s annual precipitation can vary greatly from year to year and region to region. The map of California shows how this water year’s precipitation compares to what has been observed historically. The chart below provides a summary of California’s current statewide precipitation statistics.
Precipitation Statistics (period of record: 1981-current)
Statewide as of 05/19/2022
Water Year to Date:
% of Average:
Precipitation % of average for full water year through September 30th:
Historical Record to Date:
Max:
Mean:
Min:
Percent of Average Precipitation (%)
Percent of State (%)
0-19
20-39
40-59
60-79
80-99
100-119
120-139
140-159
160-179
180-199
>= 200
Temperature as of 05/19/2022
Temperature plays a large role in California’s annual water conditions. Higher than normal
temperatures present several challenges to managing the state’s water supply. The map of California shows
how this year’s temperatures compare to what has been observed historically.
Reservoirs as of 05/19/2022
The map of California shows how reservoir conditions compare to their historical averages for this month. The metrics below are an estimate of the current total statewide reservoir storage.
Estimated Total Statewide Reservoir Storage:13.6 MAF*
Percent of Historical Average:68%
*Million Acre Feet (MAF). On average, California receives about 200 million acre-feet of water per year in the form of rain and snow. One acre-foot of water is enough to serve two families of four for a year.
Streamflow as of 05/19/2022
The map of California shows how real-time streamflow at gaged locations compares to historical streamflow ranges for the same day of the year.
Groundwater as of
The map of California shows groundwater level conditions across the state by comparing the most recent measurements
at wells to the previous 10 years of measurements for the wells. Most wells are only measured twice a year, in the spring and fall. Few wells have monthly data.
Snowpack as of 05/19/2022
The map of California shows how snowpack conditions compare to the historical averages at various locations across the state.
The plot below aggregates this same data to show how the cumulative statewide snowpack is tracking relative to the historical average.
This allows us to see how well the snowpack is doing to date, as well as how much snow may still be needed to reach the average peak snowpack (i.e., April 1st snowpack)
Percent of normal to date:
Percent of April 1st average:
Soil Moisture as of 05/19/2022
This map shows relative values of estimated soil moisture at a depth of 100 cm, as calculated from satellite-based observations.
Vegetation Conditions as of 05/19/2022
The map of California depicts vegetation conditions across the state based on the Evaporative Stress Index (ESI).
ESI provides insight on how stressed vegetation is due to a lack of water, which is expressed as the statistical variation from average conditions.