Despite widespread concern about teacher shortages, there is limited evidence on when job openings are posted and the supply of individuals applying for those openings. Using detailed job posting and application data from 19 school districts and 24 charter school organizations, we examine the seasonality of job postings, variation in applicant supply, and application patterns over the course of the hiring season. We find that 11% of jobs are posted late, with substantial variation across organizations. Regarding applicant supply, we find that school districts average fewer applicants per opening (3.3) than charters (6.1) and among districts, applicant supply is negatively associated with FRL% and positively associated with salary. In contrast, among charters, we find no statistically significant relationship between applicant supply and either student demographics or salary. Timing also matters to applicant supply: for both districts and charters, jobs posted early in the hiring season attract roughly twice as many applications as those posted in the six weeks before school starts. While descriptive in nature, our findings add depth and specificity to the existing evidence on teacher supply.