HVAC weather isn't about rain days — it's about whether you can charge accurately, survive the attic, and be safe on the roof. CrewCast checks all three for your job sites.
| Factor | Threshold | Why |
|---|---|---|
| Ambient temp (charging) | <55°F verify subcooling/superheat · <40°F unreliable | Low ambient makes AC refrigerant charging inaccurate without special procedure |
| Attic heat | ≥90°F heat index caution · ≥103°F dangerous | Attics run far hotter than outdoor air; heat illness risk is real and fast |
| Rooftop units | Wind >15 mph caution · >25 mph stop · any lightning stop | Work at height with panels and tools in wind, on the tallest point around in a storm |
CrewCast's hourly view shows when the heat index crosses your comfort line, so attic changeouts land in the morning window and condenser work fills the afternoon. The best work window rail does that math per day.
Below about 55°F ambient, standard charging by subcooling/superheat gets unreliable; below 40°F you generally shouldn't charge without manufacturer low-ambient procedures.
On a 90°F Florida day an unventilated attic can run 120–140°F. Plan attic work for mornings, hydrate aggressively, and use the buddy system on long changeouts.
Use caution above 15 mph and stop above 25 mph sustained — and any lightning within earshot means off the roof immediately.
Yes — the app is a free public beta: live radar, hourly forecasts, trade scoring, and push alerts, no account required.