NOAA has this data on the 1991-2020 U.S. Climate Normals Quick Access page.
The 2020 U.S. Climate Normals Quick Access tool provides access to data from the most recent version of the U.S. Climate Normals. This iteration of the Normals product provides 30 year averages of temperature, precipitation, and other climate variables measured at more than 15,000 U.S observation stations from 1991–2020, as well as a set of 15 year supplemental normals for 2006–2020.
The image here is a screen shot of monthly normals for one of the Ithaca, NY locations. On the top right corner of the graph there is a link to download the data, which is also in a table below the graph.