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In sagebrush ecosystems, surface soil nutrient availability, particularly of N, often increases immediately following wildfire. However, little is known on how soil N availability and other nutrients, change over time post-wildfire. In Oct., 2013 a wildfire approximately 30 km north of Reno, NV occurred in a Wyoming big sagebrush (Artemisia tridentata) community. An experiment was designed to quantify post-fire surface soil chemistry (0-10 cm) by microsite (burned and unburned canopy, burned and unburned interspace) and temporally (monthly from Nov., 2013 through June, 2015). We report on data collected through Aug., 2014. Changes in nutrient availability due to wildfire largely occurred in sagebrush canopy microsites. For all months, burned sagebrush canopies averaged nearly nine times greater in mineral N, mostly due to elevated ammonium, relative to unburned sagebrush canopies. After a 30-day laboratory incubation period, total mineral nitrogen was greater on burned shrub canopies than unburned. Burned sagebrush canopies also had greater DTPA-Mn (6 times), solution-phase sulfate (12 times), and solution-phase ortho-P (2 times) availabilities than unburned sagebrush canopies. Except for solution-phase ortho-P, the magnitude of differences in nutrients between burned and unburned canopies did not decline over the months measured. In a complimentary post-fire rehabilitation study, burned canopy microsites fostered greater seedling density and plant growth than burned interspaces, possibly due to greater availability of N and P.