Average precipitation in the lower 48 states of the United States of America.
<a href="https://en.wikipedia.org/wiki/en:United_States_Department_of_the_Interior" class="extiw" title="w:en:United States Department of the Interior"><span title="U.S. federal executive department">United States Department of the Interior</span></a>
<a rel="nofollow" class="external free" href="https://nationalmap.gov/small_scale/printable/climatemap.html">https://nationalmap.gov/small_scale/printable/climatemap.html</a>