Because San Fran is only ONE out of TWO outdoor stadiums below sea level. Makes it naturally moist.

It is a common misconception that the field is below sea level, but in actuality, it is almost 14 feet above sea level.

You cant blame them. If it were reversed, I would hope we were going to do the same thing

Candlestick Park - San Francisco, California - Home field for the San Francisco 49ers NFL football team

The problem is that when there is a high tide, the water rises below the playing surface and that is what makes the field muddy. It is never the rain falling from above that you have to worry about but the tides below...

The problem is that when there is a high tide, the water rises below the playing surface and that is what makes the field muddy. It is never the rain falling from above that you have to worry about but the tides below...

The game is at 4:30 than means it will be a night game, 7:30 Pacific in SF...

Saturday 01/14/12 3:02PM 4.61 feet High Tide
Saturday 01/14/12 5:13PM Sunset
Saturday 01/14/12 8:52PM 0.92 feet Low Tide
Saturday 01/14/12 11:31PM Moonrise

Most of the game will be played at low tide. The 4.61 is relatively low as well, considering it goes up to approx 7 within the course of the next several days. It should have little effect on the field.