Rover Environmental Monitoring Station (REMS) is a weather station on Mars for Curiosity rover contributed by Spain and Finland. REMS measures humidity, pressure, temperatures, wind speeds, and ultraviolet radiation on Mars. The investigative team is led by Javier Gómez-Elvira of the Center for Astrobiology (Madrid) and includes the Finnish Meteorological Institute as a partner. The Spanish lead project pressure and humidity sensors contributed by Finland.
Temperatures on Mars from REMS on the Curiosity Rover (August 16/17, 2012).
All sensors are located around three elements: two booms attached to the rover Remote Sensing Mast (RSM), the Ultraviolet Sensor (UVS) assembly located on the rover top deck, and the Instrument Control Unit (ICU) inside the rover. Goals include understanding Martian general circulation, microscale weather systems, local hydrological cycle, destructive potential of UV radiation, and subsurface habitability based on ground-atmosphere interaction. 
By August 18, 2012, REMS was turned on and its data was being returned to Earth. The temperature at that time: 37 degrees Fahrenheit (2.8 degrees Celsius). On August 21, 2012, one of two windspeedmeters returned data with errors. After testing it was concluded that it was broken, probably hit by a rock on descent. Martian winds can still be detected with the other sensor.
Reports are posted on the Center for Astrobiology website and twitter daily.