National Weather Service United States Department of Commerce

San Diego Mesonet

Photo of an automated weather site at Anaheim, California


Photo of an automated weather site at Julian, California

Uncle Sam

Photo of a rain gage at Elsinore, California


Photo of an automated weather site at Oak Grove RS

 What is the SDM and how will it help?

The San Diego Mesonet (SDM) is a network designed to obtain vital weather information that will increase the accuracy of forecasts and warnings from the National Weather Service (NWS) in San Diego. It is a growing network of weather stations across our region that report hourly weather information directly to our office and augments the weather network already established in our region.  How will it help us? The mission of the NWS in San Diego is to protect lives and property from the adverse affects of weather throughout a portion of Southern California replete with unique climates and countless microclimates.  Many weather phenomena are very small in scale, things like thunderstorms or strong winds, which can miss our equipment and our detection.  Southern California’s dense population increases the impact whenever threatening weather occurs. With the SDM, forecasters will know better exactly what is going on, where, and when. With this added information, more accurate forecasts and warnings are on the way.
 Where do we need it the most?

Orange County:
  • Anaheim Hills, Buena Park, Garden Grove, Irvine, Mission Viejo, etc...
San Bernardino County:
  • Desert (Phelan, Lucerne Valley, Johnson Valley, etc...)
  • Mountain (Cajon Pass, Lake Silverwood, Big Bear Lake, Forest Falls, etc...)
  • Valley (Upland, Highland, Fontana, Redlands, Yucaipa, etc...)
Riverside County:
  • Desert (Desert Hot Springs, La Quinta, Oasis, Salton City, etc...)
  • Mountain (Cahuilla, Terwilliger Valley, etc...)
  • Valley (Sage, Aguanga, etc...)
San Diego County:
  • Desert (Ocotillo Wells, North Borrego Spring, Shelter Valley, etc...)
  • Mountain (Pine Valley, etc...)
  • Valley (El Cajon, Spring Valley, Navajo, College Area, Paradise Hills, Lemon Grove, etc...)
  • Coast (Carlsbad Downtown, Rancho Santa Fe, Carmel Valley, Clairemont, Pacific Beach, North Park, Ocean Beach, Barrio Logan, etc...)


 Can I help?

We invite you to be part of the network.  To be considered, you will need to meet the following requirements:

  1. Provide a broad-band Internet connection (DSL or Cable Modem) and weather software that will automatically report hourly weather (we can help to configure your weather software) to us via ftp.
  2. Provide and maintain your weather station that includes at least temperature, humidity, wind speed and direction and a rain gauge that measures 0.01 inch increments.
  3. Agree to comply with the terms of the Terms of Agreement.

If your site is considered, we will ask you to send us digital photos to further assess the proper placement and location of the equipment. We may suggest adjustments to ensure accuracy and reliability of the data. Once confidence is attained in the suitability of your site, we will arrange to visit your site to make the final approval of the equipment siting. A technician will make the necessary computer hook-ups to transmit the data directly to the NWS office.

By helping us in this way, you can gain the satisfaction of contributing to better weather safety and awareness in our region and add to the accuracy of forecasts.  Your data will be used by NWS forecasters to monitor current weather conditions. It will also be used as input for graphical forecast algorithms that produce highly refined and detailed forecasts on our web page.

Your data will also appear on our web site as part of our observation and forecast pages.

We know there are many weather enthusiasts among you who have installed weather equipment on your property.  If you are one of these, and would like to assist the NWS fulfill our mission, please click here to submit a request application.  We will consider all the applicants, but will consider most seriously those who are located in areas where we have no equipment currently (see list above).  We’ll respond whether you are considered or not.  Thanks for your interest.

If you have any questions or concerns, please email Webmaster.

 Current SDM Map, Sample Reports, and Other Information