Hi Ana, did you use fitdist() or wblfit() to get the Weibull parameters?
One thing you can do is use qqplot() to examine the fit graphically.
data = wblrnd(0.5,0.8,100,1);
[parmhat, parmci] = wblfit(data);
pd = ProbDistUnivParam('weibull',[parmhat(1) parmhat(2)]);
qqplot(data,pd);
You can also use a Chi-square goodness of fit test with the null hypothesis that the data are drawn from a Weibull distribution with your estimated parameters:
[h,p] = chi2gof(data,'cdf',{@wblcdf,parmhat(1),parmhat(2)});
