The objective of this study is to clarify the effect of a series of windbreaks on the microclimate in a settlement. Horage settlement is located in Tsukuba City where the seasonal cold wind called“Tsukuba-Oroshi”blows in winter, and that settlement is surrounded with windbreaks. Field observations of air temperature, humidity, wind direction and velocity were conducted in winter of 2006 and 2007. The protecting effect of windbreaks against the seasonal prevailing wind was observed clearly in the daytime when the strong wind blew in the observation area. Wind velocity in the built-up area was decreased with about 45% of that in the outside of the settlement. The heat island appeared clearly in the early morning and at night when the wind was weak or calm. Daily ranges of air temperature were small in the northeast area covered with dense windbreak woods.
