We present a method for reading out the spin state of electrons in a quantum dot that is robust against charge noise and can still be used when the electron temperature exceeds the energy splitting between the states. A spin dependence of the tunnel rates is used to correlate the spin states to different charge states. A subsequent fast measurement of the charge on the dot then reveals the original spin state. We experimentally demonstrate the method by performing read-out of the two-electron spin states, achieving a single-shot visibility of more than 80%. We find very long triplet-to-singlet relaxation times (up to several milliseconds), with an in-plane magnetic field dependence consistent with spin-orbit coupling as the dominant source of relaxation.