Many radio amateurs are also interested in weather monitoring. I'm also such an "amateur meteorologist", that's why I built a small home weather station that measures temperature, humidity and atmospheric pressure.
The weather station is permanently connected to the Internet and sends data to the database on the server every minute. These data are then evaluated and displayed on the website in the form of tables and graphs. My page with this information is at http://www.depe.sk/tme/.
The weather station does not require the computer to be switched on, it is directly connected to the network via Ethernet. It is powered by a 12V source and its power consumption is only 0.8W.
A more detailed description can be found directly on the page, in the "HWinfo" tab, or in the links at the foot of the page.
Dusan, om2adp