FIRE WEATHER

Climate Central's analysis of weather station data from 225 locations across 17 U.S. states reveals a significant increase in fire weather days since the 1970s, driven primarily by warming and decreasing relative humidity. The report highlights that interior regions have seen higher increases than coastal areas, with some parts of New Mexico experiencing two additional months of fire weather compared to nearly 50 years ago. Beyond increasing wildfire risk, these conditions have led utilities like PG&E to implement public safety power shutoffs (PSPSs) to prevent equipment-related ignitions, resulting in significant economic impacts and health risks. The document argues that while land management and localized grids can mitigate risk, long-term stabilization requires reducing carbon pollution to net zero by 2050.

• Analysis of data from 1973 to 2020 shows strong increases in both the total number and the percentage of annual fire weather days across the Western U.S., with some climate divisions in California, Oregon, Texas, and Washington experiencing these conditions more than twice as often as in the early 1970s.
• New Mexico has seen some of the most significant increases in fire weather, with certain areas now experiencing two more months of such weather annually than they did nearly half a century ago.
• The increase in fire weather days is more pronounced in interior regions than in coastal regions, as the higher humidity levels typical of coasts make it more difficult to reach the low relative humidity thresholds required for fire weather.
• A small number of states in the northern plains, including North Dakota, South Dakota, Kansas, and Nebraska, saw a decline in fire weather frequency, which the report attributes to temporary cooling in springs and summers potentially influenced by natural variation and agricultural irrigation.
• Warming nights have reduced overnight relative humidity, which has negatively impacted the ability of firefighters to gain control over wildfires.
• To avoid equipment-related ignitions during fire weather, California utilities have implemented public safety power shutoffs (PSPSs); in 2019, these shutoffs left 12 million people in Northern California without power and had an estimated economic impact of $10 billion.
• Beyond weather, other factors fueling modern wildfires include the buildup of fuels due to the loss of indigenous land management, the spread of invasive grasses, urbanization of forested areas, and beetle-caused tree mortality linked to rising temperatures.

APA

Climate Central (2021). FIRE WEATHER. https://assets.ctfassets.net/cxgxgstp8r5d/4FPon4YHSWtIeFmIv1tJtw/d3f61fa19c0886cc17f2d0ba59d496e4/Climate_Central_Fire_Weather_Analysis_2021.pdf

Chicago

Climate Central. FIRE WEATHER. 2021. https://assets.ctfassets.net/cxgxgstp8r5d/4FPon4YHSWtIeFmIv1tJtw/d3f61fa19c0886cc17f2d0ba59d496e4/Climate_Central_Fire_Weather_Analysis_2021.pdf.

Wikipedia

{{cite report |author=Climate Central |title=FIRE WEATHER |date=25 August 2021 |url=https://assets.ctfassets.net/cxgxgstp8r5d/4FPon4YHSWtIeFmIv1tJtw/d3f61fa19c0886cc17f2d0ba59d496e4/Climate_Central_Fire_Weather_Analysis_2021.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{climatecentral2021fire, author = {{Climate Central}}, title = {{FIRE WEATHER}}, institution = {Climate Central}, year = {2021}, month = aug, url = {https://assets.ctfassets.net/cxgxgstp8r5d/4FPon4YHSWtIeFmIv1tJtw/d3f61fa19c0886cc17f2d0ba59d496e4/Climate_Central_Fire_Weather_Analysis_2021.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }