You can't trade it basad on fundamentals, it makes zero sense, look at historical july prices . Sometimes they are higher then jan prices. So it has nothing to do with weather.

It has everything to do with fundamental and weather, just not the weather you see when looking out the window at any given moment, but projected weather and additional data from production, storage level, exports etc. Nat gas is very fundamental and data driven, it's just insanely complex. This january was very low for example, because storage levels were high, production was high and projected weather was warm, so the assumption was that we'd end the heating season in great shape and thus at low prices, which turned out to be true.