Find the elevation range
Record both the starting elevation and highest or lowest point. Vehicle, body, and weather conditions may change along the route.
The thousand-foot rule
Plan by heat, season, and elevation
Turn one statewide forecast into a more useful decision about start times, clothing, water, road conditions, and backup plans.
The direct answer
Use the forecast for the exact elevation and time, then plan the day around exposure. A cool destination can still require a hot approach, and a warm basin can lead to snow or lightning at altitude.
Practical sequence
Do this in order.
Read hourly, not daily
High temperature alone hides sun, overnight warmth, wind, humidity, thunderstorm timing, and the length of the dangerous window.
Move effort to the safer window
Begin early enough to finish before heat or storms build. Cancel when the margin disappears.
Protect the return trip
Keep water, shade, fuel, and energy for the way back. Most turnarounds happen after the photo, not before it.
Decision criteria
Compare these before choosing.
- Overnight low and recovery time
- Sun exposure and available shade
- Altitude gain and exertion
- Monsoon, lightning, or flash-flood potential
- Vehicle and pavement heat
Common mistakes
What usually creates rework.
- Using Phoenix weather for Flagstaff or the canyon rim
- Assuming a short hike is safe in extreme heat
- Drinking only when thirsty
- Waiting for visible rain before leaving a canyon or wash
Field checklist
Leave with something usable.
Exact hourly forecast
Start, turnaround, and finish times
Water plus a reserve
Shade, sun protection, and appropriate layers
Road, trail, fire, and flood status
Source desk
Verify the part that can change.
Last reviewed July 23, 2026. Open the managing authority before making a consequential plan.