The Collaborative International Dictionary of English v.0.48:

Climatology \Cli`ma*tol"o*gy\, n. [Climate + -logy: cf. F.
   climatologie.]
   The science which treats of climates and investigates their
   phenomena and causes. --Brande & C.
   [1913 Webster]

WordNet (r) 3.0 (2006):

climatology
    n 1: meteorology of climates and their phenomena

Moby Thesaurus II by Grady Ward, 1.0:

33 Moby Thesaurus words for "climatology":
   aerial photography, aeroballistics, aerodynamics, aerogeology,
   aerography, aerology, aeromechanics, aeromedicine, aerometry,
   aeronautical meteorology, aerophotography, aerophysics, aeroscopy,
   aerospace research, aerostatics, anemology, aviation technology,
   avionics, barometry, climatography, forecasting, hydrostatics,
   kinematics, kinetics, long-range forecasting, meteorology,
   microclimatology, nephology, photometry, pneumatics, rocketry,
   supersonics, weatherology