warning message for join
Warning messages:
1: In outer_join_impl(x, y, by$x, by$y) :
joining factors with different levels, coercing to character vector
This seems to happen for any multi-site call
reproducible example:
timeZoneChange <- readNWISuv(c('04024430','04024000'),'00060',
"2013-11-03","2013-11-03")