What conditions do
Conditions decide whether a rule actually fires. When a rule runs, it checks the conditions against the real data. If they are all true, the action happens. If any is false, nothing happens.
Weather conditions you can use
Forecast is sunny is true when the day's weather is clear or mainly clear.
Max temperature is at least a value you set, in degrees. Good for hot-day prompts.
Min temperature is at most a value you set. Good for frost and cold-snap prompts.
Wind speed is at least a value in km/h. Good for securing outdoor kit.
Rain probability is at least a percentage you set.
Combining conditions
When you tick more than one condition, all of them must be true for the rule to fire. A sunny-day prompt with both sunny and at least 20 degrees will not fire on a bright but cold morning, which is usually what you want.
No conditions at all
A check-in panel rule often has no conditions, so it always shows. That is fine: leave the conditions empty and the panel appears every time someone checks in.