NWS observations within the past 24 hours are available here.
Various land management agencies such as the Bureau of Land Management (BLM) and the United States Forest Service (USFS) maintain a network of Remote Automated Weather Stations, or RAWS, across the Great Lakes states.
The ROMAN network, or Realtime Observation Monitor and Analysis Network, lists observations from a number of available observation sources including the NWS, RAWS, SNOTEL and cooperative observers. A map of observations available for Michigan is available, and use the pull down menu for data from other states.
Current and archived surface observations from several sources can be accessed through the MesoWest site.
Current observations across Michigan are available. Once a station is selected and daily data are displayed, choose the link at the bottom of the graph "Additional Tabular and Graphical Displays" to produce two week summaries or to download data.
Hourly precipitation data (in a map format) are available from the NOAA Forecast Systems Laboratory (FSL). It may take several seconds for the map to load.
If there are no observations of precipitation available for your area of interest, precipitation estimates derived from a combination of radar and observations may be useful. For anywhere in the continental U.S., precipitation estimates for different time scales are available. Use the menus to select different time scales and regions.