Zion Traverse

Weather couldn't be much better for late May in Zion. Friday stays mostly cloudy with a high of 74°F and winds under 10 mph WSW — actually ideal running conditions. Saturday and Sunday open up completely: sunny, 78–79°F, winds near zero. No precipitation in the forecast across all three days, and overnight lows in the low 40s mean comfortable camp temps. This is a rare clean window.

Heat is still your primary variable to manage, not because the temps are extreme, but because the Zion Traverse moves through exposed sandstone canyon terrain where radiant heat off the rock can push effective temps significantly higher than the ambient reading. NWS is calling 78–79°F at station level — expect it to feel closer to 85–90°F on sun-exposed south-facing walls during midday Saturday and Sunday. Hydration needs will be higher than a comparable temperature day in forest terrain. Plan water sources carefully and don't push through the exposed mid-canyon sections in the 11 AM–3 PM window if you can help it.

On pace and daylight: you've got 14 hours and 21 minutes of usable light each day, with sunset at 8:40 PM. The full Zion Traverse runs roughly 48 miles with significant elevation. If you're covering it over multiple days, daylight isn't a constraint — but if anyone in the group is targeting a single-day effort, you need to be moving by first light at 6:19 AM and averaging better than 3.5 mph including all breaks and navigation. Be honest about that math before committing to the single-push version.

Stream data available is from California gauges, which aren't relevant to this route — no useful crossing data to report for Zion specifically. No active fires within 50 miles. Snowpack at the relevant elevations for Zion is at zero (Annie Springs at 6,021 ft shows 0 inches), so no snow or ice on trail is expected. Clean go.