Precipitation & Lake Evaporation

In an effort to support Texas water resource planning activities and serve general public interests, monthly and annual precipitation and gross lake evaporation rates are provided here in a gridded format of one-degree latitude by one-degree longitude quadrangles that cover Texas. Gross lake evaporation rate is defined as water loss caused by evaporation process from lake surface, while net lake evaporation rate is defined as gross rate minus precipitation rate over lake surface. Precipitation data are available from 1940 through 2016 while gross lake evaporation data are available from 1954 through 2016. Data for a calendar year are typically added in the spring of the next year. Click here for more information on the data. Read Disclaimer below before retrieving the data (last update to data is on 10/20/2017).

Precipitation & Lake Evaporation Data

View Quadrangle Number

Output Lake Evaporation Data as:

Output Precipitation Data as:

Output Precipitation & Lake Evaporation as:


The precipitation and gross lake evaporation data posted here are based on raw data collected by multiple organizations, processed by the method for spatial distribution as specified in the information page, and are subject to revision as additional data and/or updates are made available to the TWDB. The data may be continuously updated in the future without notice. Neither the State of Texas nor the Texas Water Development Board (TWDB) assumes any legal liability or responsibility for or makes any guarantees or warranties as to the accuracy, completeness, or suitability of the information for any purpose. Please contact TWDB customer service if you have any questions or comments about the data.