How it works

What it's built on

Our model stands on world-class open climate data, decades of fine-grained records of British winters, combined with live forecasts as Christmas draws near. How we blend, weight, stabilise and sharpen all of that into a single number for your exact location is our own work. (Full data credits are in the footer.)

How we calculate the odds

For each location we start with the ground truth: how often snow has actually fallen at Christmas, year after year. Long-range daily forecasts have very little skill, so far from Christmas that history is, honestly, the best answer there is. As the day approaches and the live forecast comes into range (within about a month), our model folds it in, leaning on it more heavily each day, so the number sharpens on its own. The exact recipe, how we weight, blend and stabilise it, is our secret sauce, but it is built to be calibrated and honest rather than flashy.

Our definition of a white Christmas

We count a white Christmas as snow falling or lying on the ground at that specific location on 25 December. This is stricter and more local than the official Met Office definition (a single snowflake observed falling somewhere). It is also why our local figures look lower than the headlines you may have seen. Snow at your doorstep on the day is genuinely rare across much of the UK.

A note on accuracy

This is an independent project, free to use, for entertainment and general interest. It is not an official forecast. Weather is uncertain, so treat the numbers as guidance, not a promise.

Questions or feedback? Get in touch.