Software components are independent units of deployment which encapsulate solutions to modelling problems. Components can be used in custom developed clients, which can be from single, dedicated applications provided of a graphical user interface, to large systems. Component-oriented programming is becoming a common feature in biophysical model development where reuse and extensibility of models play an important role. In this context, the problem of weather generation was dealt with, in order to support weather-driven modelling studies with extended series of daily or sub-daily weather inputs. Two components are illustrated here, one for generation of air temperature data (namely, AirT) and the second for generation of wind speed (namely, WSpeed). The first implements three approaches (based on the assumption that air temperature generation is a weakly stationary process) for stochastic generation of daily minimum and maximum air temperature, mostly conditioned by the precipitation status of the day. Hourly estimates follow a sinusoidal time course, interpreted by alternative models. A distinct model is implemented, deriving the hourly temperature profile from the irradiance profile. Daily generation of wind speed is performed by sampling from alternative probability distribution functions (exponential, normal, skewed normal, Weibull). Probability distribution functions are even used to generate within-day wind speed values. Alternatively, cyclic functions are provided to describe diurnal wind speed variations. The components are developed using C# for the .NET platform of Windows. The architecture of both components is designed to allow for rapid integration and extension into systems of various complexity. Software features and the scientific background are fully documented in a HTML-style help. Sample Windows applications, web services, and web applications are made available as source code to show how to use and extend the components. Both components are distributed through the site http://www.sipeaa.it/tools.