Made with HERE XYZ
Snowfall in December
A map of snowfall across the US based on daily snow observations from GHCN stations. Updating throughout December 2019.
See how much it snowed on every day of December during the past four years, and come back to see how much it’s snowing this December on a daily basis. We are updating this chart as new data becomes available.
The data shown in this visualization was collected from NOAA and contains some 60,000 data points from ~15,000 weather stations, which have been measuring snowfall for the past 4 years. If you click on a state, you can explore each individual weather station, and how much snowfall it measured on a given day.
About the tools
We store, manage, and query the geographic data with HERE XYZ. 60,000 data points can be a challenge for most web data visualization tools, especially when not using WebGL. HERE XYZ enables us to easily query the relevant data gradually based on bounding box coordinates and tags, so that we can reduce the amount of data displayed to around 50-1,000 when zoomed in on a state and 2,000 when looking at the US as a whole.
For the thematic map, we chose the SVG route particularly because we are dealing with a map that shows data dependent on area size (hexagonal binning). It is customary in such situations to use an equal area projection, to preserve the area size across the map. In our case we are using the Albers USA composite projection. This also enables us to easily place Alaska and Hawaii in the viewport without rendering half a hemisphere.