Hi Mike,
until BC, normally the weather is nice and many people walk in shorts and T-shirt. The wind is mostly warm, but you can alsways encounter some rain ro hail, so be prepared for foul wether (always). At night th temperature drops to a bit above freezing, but if the weather is good, it is great to sleep outside (no tent).
Above BC the temperature drops quickly, the wind chills it down enormously and at night it can freeze a lot (most of the time the water sources of camp 1 and even BC will totally freeze and only thaw in the afternoon.
