Cal-Adapt Logo

Precipitation: Decadal Averages Map

Slow
Fast

Search for Address
Choose area selection tool for the map

12km x 12km pixel grid
Counties
Adjust the opacity of the heat map
0%
100%

legend
x
Map Controls
Use these buttons to control the map.
Zoom to the full extent of California
Zoom in
Zoom out
Search for a location
Switch between area selection types
Change the opacity of the overlay
x
Map Animation
Use these buttons to watch the map overlay reflect changes in precipitation over time.
  • Click the Play button to begin the animation.
  • Click the Toggle button to alternate between the beginning and end of the available years. The beginning year displays temperature averages projected into the past, and the end year displays temperature averages projected into the future.
  • Use the Slider to control the speed of the animation.
x
Timeline
The timeline displays which decade you are currently viewing on the map. You can manually drag the handle to change the year in view.
x
Map Legend
The Legend displays the range of values visible on the map overlay for the variable being displayed (temperature degrees, inches of rainfall, area burned, etc).
x
Map Magnifier
Click the toggle button on the bottom left corner of the map to view a magnified map. You can drag the magnified map or the magnifying glass on the larger map to explore the region.
x
Tool Charts
Click anywhere on the map to see a chart for this area.

Using the Area Selection Type Menu to the left, edit types of selection areas:

  • grid cells, where each cell is an area of 12km x 12km
  • predefined county boundaries

Then click anywhere on the map to automatically change the area described in the chart.

Select various chart options in the dropdown menus to the right, which can include Month, Model, and Temperature ranges (High, Low, or Average).

Note: The first set of chart options control the variables being viewed on the map.

x
Add a Chart for comparison

Click "Add Chart" to create an additional chart to compare with. After creating the new chart, click on a new area of the map to view a chart for the same options in another location. Or change an option in the dropdown menu to view the chart for the same location, with different settings.

To edit the first chart again, either directly edit the dropdown menus, or click on the Location Name and then click on a new location on the map.

Click "Predefined boundaries" in the Area Selection Type Menu to the left before clicking on an area of the map, if you'd like to compare counties to one another.

x
Lock Location

Fix the locations of the graphs to one area by clicking this toggle.

Elevation:
Month:
Model:

Precipitation

The following map displays the projected annual precipitation totals across the state at decadal averages.  On average, the projections show little change in total annual precipitation in California. Furthermore, among several models, precipitation projections do not show a consistent trend during the next century.

The Mediterranean seasonal precipitation pattern is expected to continue, with most precipitation falling during winter from North Pacific storms. One of the four climate models projects slightly wetter winters, and another projects slightly drier winters with a 10 to 20 percent decrease in total annual precipitation. However, even modest changes would have a significant impact because California ecosystems are conditioned to historical precipitation levels and water resources are nearly fully utilized.

Use the slider bar to the left to visualize the projected change in precipitation, as seen in the low and higher emissions scenarios. Adjust the options below to view different models, and months.

Take a Tour

Emissions Scenario:

Create a chart by clicking a location on the map and altering one of the dropdown option boxes.

Elevation:
Month:
Model:

Create a chart by clicking a location on the map and altering one of the dropdown option boxes.

Uncertainty

The data presented in this tool represent a projection of potential future climate scenarios, they are not predictions. These data are meant to illustrate how the climate may change based on a variety of different potential social and economic factors. The default visualizations in this tool are comprised of the average values from a variety of scenarios and models. Find out more about climate change data.

Disclaimer

This information is being made available for informational purposes only. Users of this information agree by their use to hold blameless the State of California, and its respective officers, employees, agents, contractors, and subcontractors for any liability associated with its use in any form.

This work shall not be used to assess actual coastal hazards, insurance requirements, or property values and specifically shall not be used in lieu of Flood Insurance Studies and Flood Insurance Rate Maps issued by the Federal Emergency Management Agency (FEMA).

Climate Tools


screen shot for the Local Climate Snapshots tool
icon for the Local Climate Snapshots tool
screen shot for the Temperature: Decadal Averages Map tool
icon for the Temperature: Decadal Averages Map tool
screen shot for the Temperature: Degrees of Change Map tool
icon for the Temperature: Degrees of Change Map tool
screen shot for the Temperature: Monthly Averages Chart tool
icon for the Temperature: Monthly Averages Chart tool
screen shot for the Temperature: Extreme Heat Tool tool
icon for the Temperature: Extreme Heat Tool tool
screen shot for the Snowpack: Decadal Averages Map tool
icon for the Snowpack: Decadal Averages Map tool
screen shot for the Precipitation: Decadal Averages Map tool
icon for the Precipitation: Decadal Averages Map tool
screen shot for the Sea Level Rise: Threatened Areas Map tool
icon for the Sea Level Rise: Threatened Areas Map tool
screen shot for the Wildfire: Fire Risk Map tool
icon for the Wildfire: Fire Risk Map tool

Precipitation: Decadal Averages Map

Climate data provided by:

California Nevada Applications Program (CNAP) logo

Scripps Institution of Oceanography

California Nevada Applications Program (CNAP)

Data Set Contributed: Projected Precipitation

Projected monthly precipitation. These data layers were downscaled using a bias correction and spatial downscaling (bcsd) approach and include data for four different models (PCM1, CCSM3, GFDL, CNRM) for two different scenarios (A2, B1).

Related Stories

Climate story photo graphic

Securing an Adequate Water Supply

2011 April 12

Continued global warming will increase pressure on California’s water resources, which are already over-stretched by the demands of a growing economy and population. Decreasing snowmelt and spring stream flows coupled with increasing demand for water resulting from both a growing population and hotter climate could lead to increasing water shortages. By the end of the century, if temperatures rise to the medium warming range and precipitation decreases, late spring stream flow could decline by up to 30 percent. Agricultural areas could be hard hit, with California farmers losing as much as 25 percent of the water supply they need.

Climate story photo graphic

Informing improved water management in the face of current and future climate variability

2013 December 05

A decade of collaboration between scientists and California water managers has led to the development of a probabilistic-based decision-support software, called INFORM (Integrated Forecast and Reservoir Management).

Climate story photo graphic

Electricity Demand

2011 April 13

Climate change may significantly affect the operation of California's electric power system, in both the demand and supply sides. As temperatures rise, electricity demand will also increase to meet air conditioning and other cooling requirements. This in turn will further escalate the emission of greenhouse gases and the air pollution due to use of unclean sources of energy.

Resources

Climate Tools

Data Access

Community

Contributors

Copyright © 2014 California Energy Commission, All Rights Reserved
State of California, Edmund G. Brown Jr., Governor
Privacy Policy | Conditions of Use | Accessibility