  We present new wind models for {\tau} Bo\"otis ({\tau} Boo), a
hot-Jupiter-host-star whose observable magnetic cycles makes it a uniquely
useful target for our goal of monitoring the temporal variability of stellar
winds and their exoplanetary impacts. Using spectropolarimetric observations
from May 2009 to January 2015, the most extensive information of this type yet
available, to reconstruct the stellar magnetic field, we produce multiple 3D
magnetohydrodynamic stellar wind models. Our results show that characteristic
changes in the large-scale magnetic field as the star undergoes magnetic cycles
produce changes in the wind properties, both globally and locally at the
position of the orbiting planet. Whilst the mass loss rate of the star varies
by only a minimal amount ($\sim$ 4 percent), the rates of angular momentum loss
and associated spin-down timescales are seen to vary widely (up to $\sim$ 140
percent), findings consistent with and extending previous research. In
addition, we find that temporal variation in the global wind is governed mainly
by changes in total magnetic flux rather than changes in wind plasma
properties. The magnetic pressure varies with time and location and dominates
the stellar wind pressure at the planetary orbit. By assuming a Jovian
planetary magnetic field for {\tau} Boo b, we nevertheless conclude that the
planetary magnetosphere can remain stable in size for all observed stellar
cycle epochs, despite significant changes in the stellar field and the
resulting local space weather environment.
