Forecast Ukraine is the Ukrainian member of the Forecast network. It puts the two European models — DWD's regional ICON-EU and ECMWF's global HRES — over the whole country and the Black Sea around it, at the same instant, on one atlas, with a forecast page for 80 places from Uzhhorod to Luhansk and Chernihiv to Yalta.

The models

• ICON-EU (Deutscher Wetterdienst) — the European nest of DWD's ICON, 6.5 km (0.0625°), eight runs a day, hourly to +48 h and three-hourly to +120 h, with 850 hPa, 700 hPa, 500 hPa and the jet. Its domain runs from 23.5°W to 62.5°E and 29.5°N to 70.5°N, so it covers Ukraine whole, with the Black Sea, the Caucasus and the plain to the Volga. The default on the maps and the first leg of every town forecast. Rendered by Forecast Germany.
• ECMWF HRES — the European Centre's high-resolution global forecast from its open data at 0.1°, four runs a day, to fifteen days, with CAPE, visibility, snow depth and 100 m wind. It takes over each town forecast where ICON-EU stops. Rendered by Forecast Euro.

Why no national model

Most European countries run a convection-permitting model of their own — Germany's ICON-D2, France's AROME, Hungary's AROME and WRF — and publish it. The Ukrainian Hydrometeorological Center does not publish open model grids, so the finest open forecast over Ukraine is DWD's ICON-EU, whose 6.5 km nest reaches the Urals, with ECMWF as the global run and the outside check. If Ukrainian model output becomes openly available, it belongs here first.

Where the frames come from

Nothing is downloaded or rendered for this site. Forecast Germany and Forecast Euro render each run once, into palettised map frames in Web Mercator with a catalog per run, and this site reads the same frames through its own server. The town pages' numbers are read back out of those frames on this server every ten minutes, at each of the 80 places, whenever a model publishes a new run.

How a number is made

Every frame is a palettised PNG whose palette is a reversible encoding of the field, published with a catalog that says how to undo it. The map shows the colours; the pointer readout, the compare panel, the city values, the point view and the town pages read the colour back to a value, to the precision of the frame's own palette — a tenth of a degree to half a degree for temperature. Wind direction comes from each model's u/v sidecar raster, and the isobars are contoured upstream from the full-precision pressure field, not from the picture. The two palettes differ, so a colour on one model is not a colour on the other — compare the values, which this site prints in one set of units (°C, m/s, mm by default; °F, km/h, knots, mph and Beaufort on the toggles).

Time

Every valid time is shown on Kyiv's clock — EET (UTC+2), or EEST (UTC+3) from the last Sunday of March to the last Sunday of October. Runs keep their UTC names. Switching model holds the valid time, not the forecast hour.

The front page, and its conic

The map on the front page is MapLibre GL JS 6.15 on a registered projection: a Lambert conformal conic drawn for the whole country, with standard parallels at 46°N and 51°N — about one sixth of the way in from Cape Sarych and from the Chernihiv border — and 31°E down the middle, on the Krassovsky ellipsoid of UCS-2000, Ukraine's national datum. On it Chernihiv and Crimea are drawn at one scale (to within a quarter of one per cent), where Web Mercator draws the north of the country 17 % larger than the south. UCS-2000's registered grids are the Gauss–Krüger zones, made for surveying strips three degrees wide, so the conic is this site's own.

The relief under it — ETOPO 2022 at 30 arc-seconds, shaded and tinted by the network's atlas maker — is rendered natively in that grid, five zoom levels deep, and ICON-EU's forecast for the present hour is reprojected over it in the browser, pixel by pixel, through the conic's own inverse. Natural Earth still draws the Kakhovka Reservoir, which emptied when the dam was destroyed on 6 June 2023; the relief here leaves it out, and the Dnipro's old bed is drawn as the land it now is. The maps are in Web Mercator instead, because that is the projection the model frames are rendered in and the one the shared basemap tiles are cut to.

Borders and names

The border drawn is Ukraine's internationally recognised one, as affirmed by UN General Assembly resolution 68/262: Crimea and Sevastopol are shown as part of Ukraine, as are all the oblasts of the east and south. This is a weather site and draws no lines of control. Place names are given in Ukrainian and in Ukraine's national romanisation (Kyiv, Odesa, Kharkiv, Zaporizhzhia), the form the UN and most English-language publications now use.

Licences and credits

• DWD: Datenbasis: Deutscher Wetterdienst (ICON-EU), CC BY 4.0.
• ECMWF: contains modified Copernicus/ECMWF open data, © European Centre for Medium-Range Weather Forecasts, CC BY 4.0.
• Basemap and geography: © OpenStreetMap contributors (ODbL) via Protomaps; borders, oblasts, lakes and rivers Natural Earth (public domain); place names and elevations GeoNames (CC BY 4.0); relief ETOPO 2022 (NOAA National Centers for Environmental Information).

Not a warning service

This is not an official forecast. For warnings use the Ukrainian Hydrometeorological Center.