Ask any of the boys from hill 437. Pouring rain, hail, and gale force wind can't stop an airsoft game.
If you know the enemy and know yourself, then you need not fear the outcome of a hundred battles.
If you know your enemy and not yourself, for every victory earned, you will also suffer a defeat.
If you know neither the enemy or yourself, you will succumb, in every battle. -Sun Tzu