Climate of 2005
Wildfire Season Summary

Wildfire activity erupted across parts of the central U.S. during December 2005, as numerous large fires developed especially in Oklahoma, Texas and the southern Plains. Many of these fires continued to burn into early January 2006. As of January 9th over 400,000 acres had burned across the southern Plains since the New Year, normally a time of very low fire activity.

Preliminary estimates from the National Interagency Fire Center suggest that 2005 will break the record set in 2000 for acreage burned, with over 8.53 million acres burned across the U.S. by the end of December. During the 2000 fire season over 8.43 million acres were consumed across the entire U.S., with over 7 million acres burned in the contiguous U.S.

Alaska had its second consecutive year with widespread wildfire activity, as over 4.4 million acres burned in 2005 across the state.

The total number of fires across the U.S. continued to decline in 2005. This fact, combined with the increase in acreage, suggests that the average size of individual fires has increased over the past 20 years.

Dead fuel moisture levels across the southern and central Plains states decreased during December. In particular, fine fuel moisture levels (i.e. 10-hour fuels) decreased below 5% across parts of Texas, Oklahoma, Arizona, New Mexico and the Front Range of Colorado during the past month.

Medium to larger fuels (i.e. the 30 December 100-hr and 30 December 1000-hr fuel moistures) were also unusually dry for the winter, especially across the Southwest and southern Plains areas.

The Keetch-Byram Drought Index (KBDI), a widely used index for fire risk, had the largest potential for wildland fire activity in the contiguous U.S. across parts of the central and southern Plains at the end of December.

For further information on drought conditions across the U.S. go to the December drought summary page.

2005 Preliminary wildfire statistics (from NIFC):

Wildfire activity re-intensified across parts of the U.S. during late November, as numerous large fires developed in Oklahoma, Kentucky, Virginia, West Virginia and the Southwest U.S. Many of these fires continued to burn into early December.

Preliminary estimates from the National Interagency Fire Center suggest that this year will break the record set in 2000 for acreage burned, with over 8.5 million acres consumed across the U.S. by early December. During the 2000 fire season over 8.43 million acres were consumed across the entire U.S., with over 7 million acres burned in the contiguous U.S. As of December 9th over 4.14 million acres had burned across the lower 48 states, which was significantly less than in 2000.

Alaska had its second consecutive year with widespread wildfire activity, as over 4.4 million acres burned this year across the state.

The total number of fires across the U.S. continued to decline in 2005, which combined with the increase in acreage suggests that the average size of individual fires has increased over the past 20 years.

Dead fuel moisture levels across the western U.S. and High Plains slowly increased during November. In particular, fine fuel moisture levels (i.e. 10-hour fuels) increased above 10% across most western states during the past month, with the exception of the southern Plains.

Medium to larger fuels (i.e. the 30 November 100-hr and 30 November 1000-hr fuel moistures) remained moderately dry at the end of November, especially across the Southwest and Great Basin areas.

The Keetch-Byram Drought Index (KBDI), a widely used index for fire risk, had the largest potential for wildland fire activity in the contiguous U.S. across parts of northern and central California and parts of the southern Plains at the end of November.

For further information on drought conditions across the U.S. go to the November drought summary page.

Year-to-date wildfire statistics (from NIFC):

Wildfire activity diminished across the U.S. during October, as the remaining large fires in the West and Rocky Mountain regions were suppressed. However, several large fires developed in the Great Plains in early November due to dry conditions in the central and southern Plains.

Typically, fire activity moves from the Pacific Northwest southward to the Southwest as the Polar jet stream shifts south during autumn. However, above normal precipitation has been observed at the beginnning of the western wet season inhibiting large fire development over the past month.

As reported by the National Interagency Fire Center, over 8.3 million acres have burned across the U.S. by the end of October, which at present ranks the 2005 season as the second worst since 1960 for total acreage burned. Currently the 2000 fire season remains the record year for the U.S. with over 8.4 million acres burned.

Alaska had its second consecutive year with widespread wildfire activity, as over 4.4 million acres have burned this yearacross the state. As of the end of October 2005over 3.9 million acres have burned across the remainder of the U.S..

Dead fuel moisture levels across the western U.S. and High Plains were dry during October. In particular, fine fuel moisture levels (i.e. 10-hour fuels) remained below 5% across most western states during the past month, with the exception of the Pacific Northwest.

Medium to larger fuels (i.e. the 31 October 100-hr and 31 October 1000-hr fuel moistures) were moderately dry at the end of October, especially across the Southwest and Great Basin areas.

The Keetch-Byram Drought Index (KBDI), a widely used index for fire risk, had the largest potential for wildland fire activity in the contiguous U.S. across parts of northern and central California.

For further information on drought conditions across the U.S. go to the October drought summary page.

Year-to-date wildfire statistics (from NIFC):

A seasonal transition in wildfire activity occurred across the U.S. during September, as the development of large fires shifted southward from the Pacific Northwest and Northern Rockies to parts of California and the Southwest. This geographical shift is typical for this time of year, as the Polar jet stream shifts southward during autumn. However, above normal precipitation during the 2004-2005 wet season enhanced the growth of brush and fine fuels across the Southwest and California, and the climatologically dry summer months have dried out these fuels and increased the potential for large fire development in these areas in early autumn.

As reported by the National Interagency Fire Center, over 8.1 million acres had burned across the U.S. by the end of September, which at present ranks the 2005 season as the second worst since 1960 for area burned. Currently the 2000 fire season remains the record year for the U.S. with over 8.4 million acres burned. Alaska had its second consecutive year with widespread wildfire activity, as over 4.4 million acres have burned across the state, while over 3.6 million acres have burned across the rest of the U.S. so far in 2005.

As is typical during the early fall, dead fuel moisture levels across the western U.S. and High Plains were dry during September. In particular, fine fuel moisture levels (i.e. 10-hour fuels) remained below 5% across most western states during the past month. Medium to larger fuels (i.e. the 29 September 100-hr and 29 September 1000-hr fuel moistures) were moderately dry at the end of September, especially across the Southwest and Great Basin areas.

The Keetch-Byram Drought Index (KBDI), a widely used index for fire risk, had the largest potential for wildland fire activity in the contiguous U.S. across parts of northern California and coastal Oregon. The potential for large fire development and spreading was evident in the fire danger classification on 29 September 2005, and remained high to very high across parts of the West.

For further information on drought conditions across the U.S. go to the September drought summary page.

Year-to-date wildfire statistics (from NIFC):

Wildfire activity continued across the U.S. during August, as numerous large fires burned in Alaska, the Northern Rockies, and Columbia Plateau regions. As reported by the National Interagency Fire Center, over 7.4 million acres had burned across the U.S. by the end of the month, ranking the 2005 season in the top five since 1960 for acres burned. The 2000 fire season is currently the record year for the U.S. with over 8.4 million acres burned.

Active fires and burned areas can be seen on the 31 August 2005 MODIS fire detections map, which shows the locations and extent of wildland fire activity in the western U.S. through the month of August (over 3.6 million acres have burned in the contiguous U.S. so far this year). Numerous large fires also burned across central Alaska during August, where over 3.8 million acres have burned this year as of August 31st.

Drier than normal conditions during the summer months have contributed to extremely low dead fuel moisture levels across the western U.S. and High Plains. Fine fuels (i.e. 10-hour fuels) remained extremely dry across the Great Basin in August. In addition, extremely dry fuel conditions have also developed across northern California and the interior Pacific Northwest over the past month.

Medium to larger fuels were also extremely dry at the end of August, especially across California, southern Idaho and the Great Basin (i.e. the August 31st 100-hr and August 31st 1000-hr fuel moistures).

The Keetch-Byram Drought Index (KBDI), a widely used index for fire risk, had the largest potential for wildland fire activity in the contiguous U.S. at the end of August across parts of northern California and coastal Oregon, along with a large area of the southern Plains and Gulf Coast region. For further information on drought conditions go to the August drought summary page for the U.S.

The potential for large fire development and spreading was evident in the fire danger classification on 31 August 2005. By the end of this past month, the fire danger classification remained high to very high across parts of the West.

Year-to-date wildfire statistics (from NIFC):

Fire activity spread northward across the U.S.during July, as numerous large fires developed across the Pacific Northwest, Northern Rockies, and Columbia Plateau regions. As reported by the National Interagency Fire Center, over 4.6 million acres had burned across the U.S. by the end of July. The area burned had surpassed 5 million acres as of mid-August, with activity increasing significantly along the Bitterroot Mountains of Idaho and Montana during the first half of August.

The majority of the large fire activity during the first half of the season occurred in the Southwest and Great Basin regions, where numerous fires continued to burn in July and early August. The locations and extent of wildfire activity in the western U.S. through the month of July can be seen on the active and burned area map from the 31 July 2005 MODIS fire detections. Significant fire activity was also observed across interior parts of Alaska and the western Yukon during July.

Drier than normal conditions across the western U.S. this summer have contributed to extremely low dead fuel moisture levels across the West and High Plains. Fine fuels remained extremely dry across the Great Basin, but dry fuels have also developed across northern California and the interior Pacific Northwest. 10-hr fuel moistures in early August were below 5% across most of these areas.

Medium to larger fuels dried out east of the Cascade Mountain range across the Columbia Plateau during July (i.e. the July 31st 100-hr and July 31st 1000-hr fuel moistures), with 100-hr fuels below 5% over most of eastern Washington and Oregon by the end of the month. The observed fuel moistures at the end of July were a significant change from those measured at the end of June for this region (i.e., see the June 30th 100-hr fuel moistures).

The Keetch-Byram Drought Index (KBDI), a widely used index for fire risk, had the largest potential for wildland fire activity in the contiguous U.S. at the end of July across parts of northern California and coastal Oregon, along with a large area of the southern Plains and Gulf Coast region. For further information on drought conditions go to the July drought summary page for the U.S.

Also note that the potential for large fire development was evident in the fire danger classification at the end of July, which remained very high to extreme across parts of eastern Washington and Montana.

Year-to-date wildfire statistics (from NIFC):

Fire activity increased dramatically during June, as numerous large fires developed across the Southwest and Great Basin regions, with activity concentrated across Arizona and Nevada. As reported by the National Interagency Fire Center, over 2.1 million acres had burned across the U.S. by the end of June. The number of acres burned had surpassed 3 million as of mid-July, with fire activity spreading eastward into New Mexico and Colorado.

So far this season the most significant of the large fire activity occurred in the Southwest and southern Great Basin areas, where numerous fires continued to burn into July. The locations and extent of wildfire activity in the western U.S. through the month of June can be seen on the active and burned area map from 30 June 2005 MODIS fire detections. Significant fire activity was also observed across interior parts of Alaska during June.

Drier than normal conditions in the Southwest U.S. in late spring and summer have contributed to extremely low dead fuel moisture levels. Fine fuels remained extremely dry across the Southwest and the Great Basin, with early-July 10-hr fuel moistures below 5% across most of this region.

Medium to larger fuels dried out across the region during June (i.e. the June 30th 100-hr and June 30th 1000-hr fuel moistures), with 1000-hr fuels below 10% over most of Arizona by the end of the month. The observed fuel moistures at the end of June were a dramatic change from those measured at the end of May, at which point the area of extremely dry fuels (below 5%) was confined to the lower Colorado River valley for both the medium (May 31st 100-hr) and large (May 31st 1000-hr) fuels.

The Keetch-Byram Drought Index (KBDI), a widely used index for fire risk, had the largest potential for fire activity in the contiguous U.S. at the end of June across the southern Plains and Gulf Coast region.

The potential for large fire development was also evident in the fire danger classification at the end of June, which remained very high to extreme across most of Arizona and New Mexico.

Year-to-date wildfire statistics (from NIFC):