Preheat oven to 500 degrees. Line baking sheets with parchment paper; set aside. In a medium bowl, whisk to combine flour, salt, sugar, and yeast. Slowly add water. The quantity you add will be determined by the humidity in the air. Transfer dough to a lightly floured work surface. Knead until soft and smooth, about 5 minutes.
Dust the dough with flour, and place in a plastic bag. Seal the bag, leaving room for the dough to expand. Let rest at room temperature for 30 minutes.
Spray work surface with cooking spray. Transfer rested dough to work surface. Divide dough into 8 equal pieces, about 2 1/2 ounces each. Roll each piece into a long thin rope, 28 to 30 inches long. Twist each rope into a pretzel. Dip each pretzel in warm water. Place on prepared baking sheets. Sprinkle lightly with pretzel salt. Let rest, uncovered, for 10 minutes.
Bake until golden brown, 8 to 9 minutes. Remove from oven, and brush thoroughly with melted butter. Continue to brush until you have used all of the butter. Serve warm, or reheat in a warm oven.