The last full moon will be on September 19, 2013 which means that September 2013 will have these 3 days to watch out for jellyfish...
Saturday September 28, 2013
Sunday September 29, 2013
Monday September 30, 2013
NOTE: You can encounter jellyfish at any time, these are just the most likely days you will see them at a south shore beach on Oahu. Check with lifeguards and posted signs before going into the water. These estimated dates are for box jellies only and other hazards such as Portuguese man-of-war can appear at any time as well.
