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. Quasi-periodic variations in solar activity and galactic cosmic rays (GCRs) ondecadal and bidecadal timescales have been suggested as a climate forcingmechanism for many regions on Earth. One of these regions is southern Brazil,where the lowest values during the last century were observed for the totalgeomagnetic field intensity at the Earth's surface. These low values are dueto the passage of the center of the South Atlantic Magnetic Anomaly (SAMA),which crosses the Brazilian territory from east to west following a latitudeof ∼  26 ∘ . In areas with low geomagnetic intensity, such as theSAMA, the incidence of GCRs is increased. Consequently, possible climaticeffects related to the GCRs tend to be maximized in this region. In this work,we investigate the relationship between the ∼  11-year and ∼  22-year cycles that are related to solar activity and GCRs and theannual average temperature recorded between 1936 and 2014 at two weatherstations, both located near a latitude of 26 ∘  S but at differentlongitudes. The first of these stations (Torres – TOR) is located in thecoastal region, and the other (Irai – IRA) is located in the interior,around 450 km from the Atlantic Ocean. Sunspot data and the solar modulationpotential for cosmic rays were used as proxies for the solar activity and theGCRs, respectively. Our investigation of the influence of decadal andbidecadal cycles in temperature data was carried out using the wavelettransform coherence (WTC) spectrum. The results indicate that periodicities of 11 yearsmay have continuously modulated the climate at TOR via a nonlinear mechanism,while at IRA, the effects of this 11-year modulation period wereintermittent. Four temperature maxima, separated by around 20 years, weredetected in the same years at both weather stations. These temperature maximaare almost coincident with the maxima of the odd solar cycles. Furthermore,these maxima occur after transitions from even to odd solar cycles, that is,after some years of intense GCR flux. The obtained results offer indirectmathematical evidence that solar activity and GCR variations contributed toclimatic changes in southern Brazil during the last century. A comparison ofthe results obtained for the two weather stations indicates that the SAMAalso contributes indirectly to these temperature variations. The contributionof other mechanisms also related to solar activity cannot be excluded. Keywords. Meteorology and atmospheric dynamics (climatology)

Effects of solar activity and galactic cosmic ray cycles on the modulation of the annual average temperature at two sites in southern Brazil