Daily cloud-modified erythemal UV index for The Netherlands

UV archive
overview

Or select
an archive day:

Date range:
01 Jan 2024
-- 17 Mar 2025

Archive days
without cloud data:
17 Aug. 2024
01 Nov. 2024

 
For measurements of
today's UV index at
RIVM (Bilthoven), see
this page (= in Dutch)

Introduction The plots on this page show for selected places in The Netherlands the UV index throughout the day, both cloud-free (thin blue line) and cloud-modified (red line/points) -- if the latter is absent, then cloud cover data is not available. Today's cloud-modified UV index (available as of about 04:30 UTC) is updated when new cloud cover data arrives, which usually is every 15 minutes -- you may have to use shift-reload to see the latest images. Data from 2024 has been reprocessed to provide some comparison.

[ basemap: Wikimedia ]

Some info on the data file The data file contains the cloud-free and cloud-modified UV index for an area covering The Netherlands for each quarter of an hour from 03:00 UTC up to and including 21:45 UTC, both in the usual non-dimentional unit, and given with 3 decimals. For quarters with insufficient sunlight to determine the UV index or the cloud data or with missing cloud data, the entries have fill-values (-1.0). The original resolution of the data is the same as the standard UV grid: 0.25 by 0.25°. The line plots shown above are extracted from these data. A version at higher resolution is made by interpolating the cloud-free data to 0.05 by 0.05° and then averaging the cloud data over 0.15 by 0.15° around the grid cell center. This "hr" version is available as of 11 February 2025 (back-processing of the archive is not feasible). The example maps on the right show the area that is covered by the data: longitude = 3.00 – 7.75°E, latitude = 50.25 – 54.00°N, at: (top) the original resolution, i.e. divided in 19 by 15 grid cells of 0.25 by 0.25°, and (bottom) the higher resolution, i.e. divided in 95 by 75 grid cells of 0.05 by 0.05° Most important global attributes: data_product_date = date of the data in the file date_created = date the data file was created latest_cloud_modified_time = UTC time of the last time slice filled with cloud-modified UV index data data_product_status = "near-real time" for the operational processing (as of 5 Dec. 2024) or "archive" for reprocessing data   Main data variables: uvi_clear = Erythemal UV index cloud-free uvi_cloudy = Erythemal UV index cloud-modified status = Status of cloud-modified data:   0 = not available   1 = available for at least one grid cell   2 = forecast cloud data used (reserved flag) plus grid cell coordinate & time data. Data file(s) can be downloaded from the links provide above under the graph with the date in the filename. Today's data is also available with a static filename via: * https://www.temis.nl/uvradiation/UVI/uviec_nl.nc == 0.25 degree * https://www.temis.nl/uvradiation/UVI/uviec_nl_hr.nc == 0.05 degree

Example plots of the cloud-free and cloud-modified UV index at 12:00 UTC for 21 June 2024 at a resoltion of 0.25 by 0.25° (above) and 0.05 by 0.05° (below)