A quality-controlled data service of volunteered weather observations

In 2011, the UK Met Office launched a citizen science project intended to collect data from citizen weather stations (CWS) and, to date, the Weather Observations Website (WOW) project has collected over 1,400 million observations worldwide collected by over 17,000 CWS. The Dutch Met Office (KNMI) joined this project as a partner in 2015 and currently, 500+ CWS monitor the weather in the Netherlands producing over 2 million volunteered weather observations per month.