Snowpoint city & weather events

[Mr. Brightside]

So according to Bulbapedia:
On January 10, 2008, Junichi Masuda posted a blog entry urging players to play their Diamond or Pearl January 12. On that day, the same day as Masuda's birthday, a weather effect called diamond dust occurred in Snowpoint City, replacing the usual snow. It resembles glitter in the air. It is purely aesthetic, since it only occurs within the city where no battles are possible. It has been determined that other special weather conditions such as thunderstorms happen on predetermined days throughout the year.

I got to Snowpoint city a few weeks ago, and the first time i entered the city i saw this dust. So i was wondering, aside from Masuda's birthday are there other days where you can get this effect? Or it was added as one you see the first time you reach Snowpoint city in Platinum?

Also, have you seen any other special weather conditions?

[classy_cat18]

It's totally random. They even mention it sometimes on the TV programs. I think I read somewhere that the chance of running into the "Diamond Dust" is 1 in 1000, but I've witnessed it on Platinum about three times already. This is the only special weather condition I've witnessed there.

[Mr. Brightside]

Funny enough on Friday as i was walking on route 213 the screen became darker so i took a step back to Valor Lake and light came back. So on Friday route 213 was cloudy. It was so awesome XD