Help! Clutch pedal waaay too stiff. Makes the car not fun.

[aBsOlUt]

I just had about 4 weeks ago the 15k service. I requested brake fluid change but not clutch fluid, unless they did it. Would be better if I get more involved about what they do with my car. However, they did provide a huge list of things they changed on the 15k service with an official signature of a techinician.

Should I tell them to change the fluid? Why do I see a significant difference based on weather?

Thanks alot of your response!