Snap Raster (Environment setting)

Tools that honor the Snap Raster environment will adjust the extent of output rasters so that they match the cell alignment of the specified snap raster.

A Snap Raster is typically used where inputs to tools:

Learn more about how Snap Raster works

Usage notes

Dialog syntax

Snap Raster—Sets a raster that is used to define the cell alignment of an output raster.

Scripting syntax

arcpy.env.snapRaster = raster




The raster to be used as the snap raster.

snapRaster syntax

Script example

This example demonstrates how to set the snap raster environment before executing a Spatial Analyst tool.

import arcpy

# Set general environments
arcpy.env.workspace = "C:/workspace"
arcpy.env.extent = "C:/data/studyArea"

# Set Snap Raster environment
arcpy.env.snapRaster = "C:/data/my_snapraster"

# Set local variables
InZones = "C:/data/parcels.shp"
InZoneField = "Parcel_ID"
InValueRaster = "C:/data/Slope"

# Check out ArcGIS Spatial Analyst extension license

# Process: Calculate the mean slope of each parcel area.
out =, InZoneField, InValueRaster, "MEAN","DATA")"mean_ParSlp")

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