DOI: 10.3886/e233241v1
title: Climate.gov Data Snapshots: Historic Probability of Large Wildfire

description: <b>Q: Where is the chance for wildfires enhanced at this time of year?
</b><b>
 </b><br><b>A:</b> Shading
 on each map reflects how often fires with an area of 100 acres or 
larger were reported within 25 miles during a 24-year base period. The 
darker the shading, the higher the number of fires reported close in 
time to the displayed date.

 
 <br><b>Q: How were these maps produced?
</b><b>
 </b><br><b>A:</b> Using
 daily fire records from the beginning of 1992 through the end of 2015, 
meteorologists who specialize in predicting fire weather plotted all 
fires of 100 acres or larger on a map. Grid lines on the map divide the 
entire area into rectangles—called grid cells—approximately 50 miles on a
 side. For every day of the year, scientists counted the number of years
 each grid cell contained at least one qualifying fire, and then divided
 by the total number of years.

To reveal the long-term pattern of fires, scientists applied 
mathematical filters to smooth the raw counts, both across the land 
(spatially) and through the year (temporally).

Fire locations and sizes were originally obtained from the U.S Forest Service Fire Program Analysis Fire-Occurrence Database.

 
 <br><b>Q: What do the colors mean?</b><b>
 </b><br><b>A: </b>Shaded areas show the historical probability of a wildfire that covers 100 acres or more occurring within 25 miles.

 
 <br><b>Q: Why do these data matter?</b><b>
 </b><br><b>A: </b>Knowing
 when and where large wildfires occur through the year can promote 
preparedness. Residents who are alert to the possibility of wildfires 
are better able to respond in ways that can keep them safe. These maps 
can also help firefighting agencies plan for when and where their 
services and equipment may be needed.

 
 <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. NOAA's National Weather Service Storm Prediction Center produced 
the original Probability of a Wildfire ≥ 100 acres files. To produce our
 images, we obtained the map data, and ran a set of scripts to display 
the mapped areas on our base maps with a custom color bar. See box at 
right for a link to the original data source.

 
 
 
 <br><b>References</b>
 
 Short, Karen C. 2017. Spatial wildfire occurrence
 data for the United States, 1992-2015 [FPA_FOD_20170508]. 4th Edition. 
Fort Collins, CO: Forest Service Research Data Archive. https://doi.org/10.2737/RDS-2013-0009.4
 <br>Source: https://www.climate.gov/maps-data/data-snapshots/data-source/historic-probability-large-wildfire
 




<br><br>This upload includes two additional files:<br>* Historic Probability of Large Wildfire _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/historic-probability-large-wildfire)<br>* Cimate_gov_ Data Snapshots.pdf is a screenshot of the data download page for the full-resolution files.<br><br><br><br>
description: One image for each day of the year.<br><br>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.