Pick a city for the month-ahead view. Days 1-14 come from live weather models; days 15-30 show what is typical for those dates from 30 years of climate records — a planning tool, not a literal day-by-day promise.
Days 1-3 verify around 85% of the time, days 7-10 near 60%, days 11-14 about 45%. After that the atmosphere is genuinely unpredictable day-to-day, which is why our days 15-30 show the typical range for those dates from 1991-2020 records rather than pretending to know.
The forecast half leans on NBM, ECMWF and GFS and refreshes with each model run. The back half of the month is a statistical corridor drawn from three decades of records — it tells you what's typical, never what's certain.
No — and be wary of any site that claims otherwise. Past two weeks, only climate statistics remain. Come back once your date slips under 14 days out; under 48 hours you'll get it hour by hour.
Two clocks tick on this page: the forecast half updates with every model cycle, several times a day, while the climate corridor only changes when the calendar month does.