In North Carolina, winter annual weeds are the primary source of TSWV inoculum that is spread to susceptible crops in late spring by Frankliniella fusca Hinds. To test the hypothesis that rainfall negatively affects populations of F. fusca and the increase of TSWV incidence within winter annual weeds, the precipitation levels and timing were manipulated to mimic 2002, a year during which TSWV incidence in crops reached record levels, and 2003 when minimal TSWV incidence was reported in susceptible crops. Seven experimental treatments were established over identical patches of common chickweed (Stellaria media) infested with F. fusca. The treatments included a low level of precipitation, which mimicked rainfall patterns of 2002; a high level of precipitation, which mimicked 2003 rainfall; and ambient rainfall for 2004. The remaining treatments included 2003 patterns of rainfall during only February, March, April, or May, with 2002 rainfall patterns during other periods. The overall abundance of F. fusca on S. media differed among treatments with greatest numbers collected from the low precipitation 2002 treatment and lowest numbers from high precipitation 2003 and April treatments. TSWV incidence differed significantly among treatments and indicated that April rainfall events had the greatest influence on reducing spread within S. media patches. Knowledge of how rainfall events affect populations of F. fusca and TSWV spread may be a useful indicator for predicting the time when susceptible crops are at highest risk of TSWV infection.