here's a world weather website - take a look on there http://worldweather.wmo.int/

You can find live weather details on holidaysuncovered.co.uk just click on the enter the review site then another menu appears at the bottom with weather underlined. This gives you live weather details for all the holiday resorts.
If you want a few days you can click on bbc weather and put in Thessalonika and it will give you five days but I think this temperature is taken in a slightly cooler place near the city rather than the Kassandra Pennisula.
Have a great holiday, Im sure you will.
Out to Hanioti myself soon!