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.
Weather observations are typically collected by professional devices siting in open spaces. These weather stations provide very precise measurements, but they also require a regular maintenance and calibration of the sensors, which implies a high cost for national weather services. In general terms, one could say that we are good with the current weather forecast. In the end, the combination of in-situ measurements with numerical weather models and remote sensing data, provides a decent weather forecast for several days in advance.