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The cumulative vapor pressure deficit—an indicator of how strongly the atmosphere would have been pulling moisture from the soil and plants—in the immediate vicinity of the Marshall Fire was the highest on record (dark brown) during October–December. Most of the surrounding area in both the mountains to the west and the prairie and agricultural land to the east was very dry (light brown), falling in the 90^th percentile (meaning the driest 10 percent of the historical record). Image from the Climate Toolbox website.