1. Fluctuations in abundance of blacklegged ticks in space and time are well‐documented, but the extent to which populations fluctuate synchronously across habitat types is poorly understood. In oak forests, blacklegged tick density depends on small mammal abundance, which is in turn driven by fluctuations in acorn production. It is currently unknown whether fluctuations in tick abundance in oak forest, long understood to depend largely on masting events, are shared with nearby non‐oak forest. 2. In this study, we analysed 22 years of tick population data from nine forest plots in south‐eastern New York in order to compare fluctuations of nymphal and larval blacklegged tick populations in oak‐dominant forests and non‐oak forests. 3. We found that population peak densities of nymphal ticks were strongly synchronous in oak and non‐oak forests among years and that larval population dynamics were weakly synchronous between these two forest types. 4. Our results suggest that drivers of immature tick density in oak‐dominant forest, including climatic factors and mast‐driven host dynamics, may also influence tick population fluctuations in the surrounding landscape.