Appearance: colourless odourless gas
Melting point: -182 C
Boiling point: -164 C
Vapour density:
Vapour pressure:
Density: 0.717 g/l at 20 C.
Flash point: -221 C
Explosion limits: 5 - 15%
Autoignition temperature: 537 C
Water solubility: slight (35 ml/l at 20 C)

In the event I didn't make myself clear, methane will go BOOM between concentrations of 5 and 15 percent. The choice one has in some situations is to get the concentration over 15% or under 5%.

Thanks, Richard.