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Post-wildfire revegetation projects often fail possibly due to seedling mortality associated with soil drying in spring.  In order to improve plant material selection for specific sites, we previously developed models to predict potential seminal root growth of several revegetation species. Yet, application of these models to site specific conditions requires quantification of initial spring drying and rewetting conditions, as well as the root zone thermal environment.   We quantified the time to the first soil drying period, frequency of subsequent rewetting and drying rates, as well as wet-degree days for five temperature ranges (0 - < 5 C°, 5 - < 10 C°, 10 - < 25 C°, 25 - < 30 C°, and 30 - < 35 C°) at four soil depths (1-3 cm, 13-15 cm, 18-20 cm, and 28-30 cm).  We also tested the effects of site, prescribed burning, cut & drop, woodland infilling phases, and three microsites (tree drip line, shrub, and interspace) on each variable. These variables were derived by measuring soil water potential and temperature with gypsum blocks and thermocouples at nine sites.  In general, we found that soil drying followed a top to bottom drying pattern with an average of 37±9.3, 75±10.3, 82±10.6, and 87±10.2 days from march 1st to the first drying period at the respective soil depths.  The frequency of subsequent rewetting averaged 4.2±0.4, 1.7±0.2, 1.5±0.1, and 1.3±0.03 times at each respective soil depth.  Soil drying rates varied between sites  and soil depth. Cool temperature ranges increased in wet-degree days with deeper soil depths. For at least some years since treatment, prescribed burning, cut & drop, and increased woodland infilling increased days to the initial drying period.  Quantification of soil drying, rewetting, and thermal environment of seedling root zones in the spring may improve site specific application of root growth models.