MeV to multi-TeV thermal WIMPs are all observationally allowed

We consider a weakly interacting massive particle (WIMP) dark matter (DM) annihilating into all possible Standard Model particle pairs, including the neutrinos, via $s$-wave processes and derive the branching ratio independent upper limit on the total annihilation cross-section $\langle \sigma v \rangle$ using the data of several astrophysical and cosmological observations. For conservative choices of all astrophysical parameters, we obtain upper limits of $10^{-23}-10^{-25}\,{\rm cm}^3{\rm s}^{-1}$ on the total $\langle \sigma v \rangle$, for the WIMP mass range $10\,{\rm MeV}-100\,{\rm TeV}$, thus making the entire mass range consistent with the observed relic density.