Most travel advice stops at naming the single best month to visit a place, which is rarely much help when your dates are dictated by work, school terms or the price of flights. The year calendar takes the opposite approach. Pick one of the 24 destinations and the tool scores every one of the 52 weeks of the year against your saved weather preferences, then lays the whole year out as a single heatmap so the warm, dry stretches and the cold, wet ones are visible side by side at a glance. Beneath the grid it draws the Dutch school-holiday periods for the Noord, Midden and Zuid regions as labelled bands, so you can see where good weather and family availability actually overlap rather than guessing. A short list of the five highest-scoring weeks is highlighted with their date ranges, and clicking any week opens a panel breaking the score down into temperature, rain, sunshine and wind. It is built for matching your real diary against the climate, instead of bending the trip around one headline month.
When you choose a destination and select a school-holiday region, the tool requests roughly twenty years of daily records from the Open-Meteo Historical Weather API for that place's exact coordinates, covering each of the 52 weeks in turn. The heatmap is therefore computed live from that archive at the moment you run it, not read from a precomputed table. Each week's daily values for mean temperature, precipitation, sunshine duration and wind speed are averaged across those two decades and scored against the same preferences and the same algorithm used by the single-destination check, so a week here and that date range on the check page agree. The four components are combined into one number out of 100 in which temperature carries the largest weight at roughly 35%, rain and sunshine carry an equal middle weight of roughly 25% each, and wind carries the least at roughly 15%. Cell shading reflects that combined score, with stronger colour for higher-scoring weeks, and the five best weeks are surfaced separately. Because these are long-run averages and not a forecast, a green week tells you the climate is usually favourable then, not that any specific year will be.
No. Every week's score is built from roughly twenty years of historical daily records averaged together, so it describes what the weather is typically like in that week, not what it will do in any particular future year. It is reliable for planning the rough timing of a trip months ahead, but it cannot tell you whether a specific week will actually be sunny or wet.
Weeks give you finer resolution than months for choosing dates. The conditions in early June can differ noticeably from late June at many destinations, and a monthly view would hide that. Scoring all 52 weeks lets you see exactly where within a month the weather tends to turn, which matters when you are fitting a trip into a fixed window.
The averaged temperature, rainfall, sunshine and wind for that week are compared against the weather preferences you set, then combined into a single score out of 100. Temperature carries the largest weight at roughly 35%, rain and sunshine an equal middle weight of roughly 25% each, and wind the least at roughly 15%. It is the same algorithm the single-destination check uses, so the two stay consistent.
They mark the Dutch school-holiday periods for the Noord, Midden and Zuid regions, drawn as labelled horizontal bands aligned to the weeks they cover. They are there so you can see at a glance which good-weather weeks coincide with family availability, and which fall in the busier, more expensive holiday peaks you might prefer to travel around.
The heatmap is computed live from the Open-Meteo historical archive when you run it, fetching about twenty years of daily data for every week at the destination's exact coordinates. That is a lot of records to gather and average, so there is a short progress step. Results are cached in your browser, so running the same destination again is much faster.
Yes. Clicking any week in the heatmap, or any of the five highlighted best weeks, opens a panel that breaks the score into its temperature, rain, sunshine and wind parts with the underlying averages. From there you can open that exact date range on the destination check page to see the full breakdown for those dates.