DOI: 10.3886/e233227v1
title: Climate.gov Data Snapshots: Precipitation - Monthly Total

description: <b>Q: How much rain and snow fell through the month?
</b><b>
 </b><br><b>A:</b> Colors
 show monthly precipitation totals across the contiguous United States. 
The darker the color, the higher the total precipitation.

 
 <br><b>Q: Where do these measurements come from?
</b><b>
 </b><br><b>A:</b> Daily
 measurements of rain and snow come from weather stations in the Global 
Historical Climatology Network (GHCN-D). Volunteer observers or 
automated instruments gather the data and submit them to the National 
Centers for Environmental Information (NCEI). After scientists check the
 quality of the data to omit any systematic errors, they calculate each 
station’s monthly total precipitation and plot it on a 5x5 km gridded 
map. To fill in the grid at locations without stations, a computer 
program interpolates (or estimates) values, accounting for the 
distribution of stations and various physical relationships, such as the
 way temperature changes with elevation. The resulting product is the 
NOAA Monthly U.S. Climate Gridded Dataset (NClimGrid).

 
 <br><b>Q: What do the colors mean?</b><b>
 </b><br><b>A:</b> Areas
 shown in white received little or no measurable precipitation for the 
month. Areas shown in the lightest green received less than one inch of 
water from rain or snow. The darker the color on the map, the higher the
 precipitation for the month. Areas shown in dark blue received eight 
inches or more of precipitation that fell as either rain or snow. Note 
that snowfall totals are reported as the amount of liquid water they 
produce upon melting. Thus, a 10-inch snowfall that melts to produce one
 inch of liquid water would be counted as one inch of precipitation.

 
 <br><b>Q: Why do these data matter?</b><b>
 </b><br><b>A:</b> Farmers
 and gardeners who depend on rain for their plants want to know if 
enough precipitation has fallen to support plant growth. Similarly, 
forest managers and ranchers check monthly precipitation to monitor the 
status of the environment. Water managers who work to ensure that towns 
and cities have enough water for drinking, washing, and industrial uses 
are also interested in how much precipitation falls each month.

 
 <br><b>Q: How did you produce these snapshots?</b><b>
 </b><br><b>A:</b> Data
 Snapshots are derivatives of existing data products; to meet the needs 
of a broad audience, we present the source data in a simplified visual 
style. This set of snapshots is based on climate data (NClimGrid) 
produced by and available from the National Centers for Environmental 
Information (NCEI). To produce our images, we invoke a set of scripts 
that access the source data and represent them according to our selected
 color ramps on our base maps.

 
 <br><b>Q: Data Format Description</b><b>
 </b><br><b>A:</b> NetCDF (Version: 4)

 
 Additional information
 The data used
 in these snapshots can be downloaded from different places and in 
different formats. We used these specific data sources:

NClimGrid Total Precipitation

 
 References
 
 NOAA Monthly U.S. Climate Gridded Dataset (NClimGrid)<br>
NOAA Monthly U.S. Climate Divisional Database (NClimDiv)<br>
Improved Historical Temperature and Precipitation Time Series for U.S. Climate Divisions<br>
NCEI Monthly National Analysis<br>
Climate at a Glance - Data Information<br>
NCEI Climate Monitoring - All Products
 <br>Source: https://www.climate.gov/maps-data/data-snapshots/data-source/precipitation-monthly-total <br><br>This upload includes two additional files:<br>* Precipitation - Monthly Total _NOAA Climate.gov.pdf is a screenshot of the main Climate.gov site for these snapshots (https://www.climate.gov/maps-data/data-snapshots/data-source/precipitation-monthly-total )<br>* Cimate_gov_ Data Snapshots.pdf is a screenshot of the data download page for the full-resolution files.<br><br><br><br>
description: Data is divided in to folders by image resolution -- full size (zip), small (png) and large (png). Occasionally there may be one image missing in a particular size but available in another size.<br><br>Data downloaded from climate.gov 6/17/2025.