Pack for temperature bands and rain likelihood, not for a single icon five days out. UK weekends often flip after a midweek model update.
On meridian, lock waterproof and layers from the daily ribbon; lock leave-time from the hourly strip within 24–48 hours of travel.
If two destinations disagree, pack for the wetter and windier of the pair. It is easier to shed a layer than to invent a coat.
Refresh the place page the evening before you go. Free-tier forecasts improve as the event approaches — that is expected, not a failure of earlier views.