To make the Typhoon go away just check the weather channle until it says "tommorrow there will be a typhoon" before you go to bed enter any of the following codes (you'll need either a gameshark or the rom and emulator, I suggest project 64, works great for me and I have a rather slow computer.)
802373A9 0001 sunny
802373A9 0002 rainy
802373A9 0003 snowy
802373A9 0004 sunny rain with sunny music
(the rain dosen't water your plants, but people will be inside)
I am sorry to those who can't afford the gameshark or don't have a computer, but there is no other way to completly avoid random summer typhoons. Unless praying to the goddess for weather really does effect it(most people say it takes effect two days after you pray, something about weather that's forcast can not be changed, I'd rather not throw eggs in all summer to find out)
If you need help entering the code in the emulator pm me. I think you can do that here. Though I'm only familiar with project 64 and not any other N64 emulators.
Finally your search for a no typhoon cheat is over!
Edited: Apr 19 2011
Added by: erossirraf Apr 12th 2011, ID#6552