Shape-memory　alloy　(SMA)　knee-braced　frames　(KBFs)　are　a　type　of　seismically　resilient　frame　buildings.　Knee　braces　(KBs)　in　this　system　are　the　SMA　buckling-restrained　braces,　which　provide　both　self-centering　and　energy-dissipating　capacity.　SMAs　are　known　for　their　noticeable　thermal-mechanical　property,　but　there　remains　a　lack　of　understanding　regarding　the　temperature　effect　on　the　seismic　responses　of　SMA　KBFs.　Hence,　this　study　aims　to　address　this　issue　at　both　component　and　system　levels.　Cyclic　loading　tests　were　conducted　on　reduced-scale　SMA　KB　specimens　under　five　distinct　ambient　temperatures　ranging　from　-20　degrees　C　to　20　degrees　C.　The　experimental　data　were　then　used　to　quantify　the　relationship　between　the　hysteretic　parameters　of　interest　and　the　ambient　temperature.　At　the　system　level,　a　multistory　steel　frame　located　in　Tangshan　City,　China,　was　selected　as　the　example　structure.　The　probability　density　function　was　built　to　describe　the　temperature　variation　of　the　selected　region,　and　the　parameters　of　the　function　were　determined　using　the　maximum　likelihood　estimation　method.　The　probabilistic　analytical　framework　that　considered　the　temperature　effect　was　described.　Then,　this　work　conducted　seismic　design　at　the　reference　temperature　(20　degrees　C).　In　what　followed,　within　varying　temperature　conditions,　nonlinear　time-history　analysis　and　multistripe　analysis　were　conducted.　The　seismic　response　indexes　under　discrete　temperature　levels　were　compared.　Finally,　the　temperature　effect　was　understood　by　generating　the　joint　fragility　curves　under　various　levels　of　temperature　and　seismic　intensity.　The　findings　indicated　that　the　temperature　effect　on　SMA　KBs　was　noticeable.　However,　the　temperature　effect　on　SMA　KBFs　was　minor,　even　though　the　extent　of　temperature　variation　was　up　to　60　degrees　C.