Arduino Heater Control

This is my first time posting in this section, and to be frank, I know nothing about it (please help). I am trying to build an arduino rain sensor, and I want it to be accurate. This means I must have a heater to evaporate the rain so the arduino doesn't think it is raining 2 hours after the rain has passed, because in England there are lot's of showers.=D. I have no clue how you get an arduino to run a heater, and would be very grateful for your help.

Thanks.

There are solid state relays which can be driven directly from the Arduino. Search for "SSR-25DA".

There are simple humidity sensors, like the DHT11 and the DHT22, see the playground section: http://arduino.cc/playground/Main/InterfacingWithHardware#envhum

To accurate measure if it is raining, perhaps you could use a rain measering device from a weather station. This method is not very reliable : http://www.youtube.com/watch?v=E6VSQThHkSM The sensor could get dirty, causing it to think that it is raining.

There is a lot information about rain sensor, like this one: http://arduino.cc/forum/index.php?topic=73001.0

I like this one : https://www.sparkfun.com/products/8942? It has a self-emptying bucket type rain meter. That seems reliable.

Edit: I think I misunderstood your question. Your goal is to measure the rain, and not to turn on a heater ? So you only want to detect if it is raining or not, or do you want to measure the amount of rain ?

I want to know just if it raining or not, I have already worked out how to do this, but it is not accurate, so i wanted to know how to turn a heater on when it is raining, which will evapourate the water so if it is not raining it will be dry, and not still wet from the rain.

Your answer solved my question though!
Thanks!