Beyond about two weeks, forecast models carry almost no skill, so the honest price for a distant weather market is the historical frequency adjusted for trend and for whatever El Niño-style pattern is in place. Long-dated weather markets nonetheless get bid around by recent conditions — a hot week in June moves an August contract that the weather in June tells you nothing about. You anchor to climatology and fade the recency.
Markets on Polymarket where climatology anchor for long-dated weather is the natural play: