Since 2006, I have maintained weather stations in multiple differn't locations. My most popular one is the one located up on Pikes Peak, OR

Why?

The original reason I started with weather stations was to check on the weather up on the mountain before jumping on the motorcycle and riding up the mountain. More then once, I had been suprised about the cold and windy weather up on the many times and wanted to check before going up the mountain.
I started shopping for weather stations, on a budget, and tried to find the cheapist weather station I could find that I could hook up to a computer to log the data and publish it on the internet.

What I did

The weather station I found was well known as a One Wire Weather Station made by AAG Electronica (Link may or may not work) I could get a complete weather station together and ready to roll for $200 ($70 for the weather station and $130 for a Dell GX150 running Linux)
I spoke to the staff at Pocket Inet and told them my desire to install a weather station up on a mountain and was offered a deal I could not pass up. They would let me put in a weather station on the tower at Pikes Peak for free, IF I also put up a webcam. I agreed and purchased an outdoor IP webcam, and headed up the mountain to install it.
I installed Pikes Peak, then I installed one just like it at my residence. And then got a couple calls and installed a couple more stations at my parents residence and another one at my old employer at the farm, 10 miles north of Prescott.

What I learned

I have had some failures and learned some lessons. I have had the bearings wear out on the anemoter, its been hit by lightning, I have had bolts fall out, and I have had the weather station fail in the middle of the winter when the road is closed for the season. It can be rough maintaining equipment on top of a mountain, you have to be ready to run up the moutain any time of the year is just about any weather.
The gear up on a mountain top will endure some pretty rough weather, wind, hail, heat, UV rays, all will slowly degrade any equipment on a mountain top.
Equipment - You will need an off road vehicle that can go up a bumpy/muddy/snowy road and haul some gear. I have used my TW 200, my XT 350, and my Dodge Cummins Diesel depending on what I need to change on the weather station. You will also want some good climbing gear and tool bag.
Also, it can be expensive, be ready to replace all of the gear because it got hit by lightning (So far, its happened to me once, totalled all of my equipment on the mountain)
Power - Any weather station is useless if it looses power during a storm. Make sure you have a battery backup setup to power the station and data logger during a power outage.

A little bit about differn't weather stations

I have installed a couple differn't weather stations, including One Wire Weather, Lacrosse (2310), and Davis (06152C). Overall, they all work, but the most accurate and easiest to work with has been the Davis Vantage Pro 2.

Regardless of what decide to go with, do your homework and plan ahead a couple of years. Also, for wind measurement, make sure you go with a cup style wind guage, the fan style does not work well.