Climate extremes are critically important for structuring wildfire behavior and impacts. Here, we describe three studies that draw upon satellite observations and models to explore fire dynamics during periods of extreme fire weather. First, we use fire event tracking datasets to quantify the functional relationship between vapor pressure deficit and fire spread rate in temperate and boreal forest ecosystems, focusing on the environmental factors associated with periods of explosive fire growth (i.e., the top 95% of 12-hourly fire growth rates from 2012-2023). Second, we use a global fire atlas to explore how heatwave duration influences fire properties within and across biomes and continents. We then use region-specific sensitivity factors derived from this analysis with simulations from the Community Earth System Model 2 Large Ensemble (CESM2-LENS) to estimate how heatwaves will modify fire occurrence and burned area during 2030-2050. In a third analysis, we simulate pyrocumulus cloud formation and atmospheric response from the 2020 Creek Fire in California using the Energy Exascale Earth System Model (E3SM). Finally, we describe key research challenges to represent better extreme wildfire behavior and megafire events within earth system models.