Astronomical observations are strongly dependant from weather, this is obvious! So I've installed a cheap weather station to monitor the main meteorological parameters. The station is a LaCrosse WS2350, a classical affordable solution between amateurs. The price in 2009 was around 130 €. I've added a solar shield for accurate temperature measurements: this was made by meteo expert Luigi Carbonera. Thanks!
The positioning is near my observatory, in my garden at city center, at about 4 m height.
The main measurements are:

• temperature
• relative humidity
• wind speed and direction
• rain quantity

I'd like to add some more stuff in the future.
The meteo measurements are available in real time from this page.