Larry Dighera wrote:

A Piper PA28-235 can have 84 gallons of fuel in 4 tanks, so leaving
them half empty, for instance in a humid maritime environment,
overnight where the temperature drops sufficiently to cause the
moisture to condense out of the 40 gallons of air contained in them,
will result in enough water in the fuel system to interfere with
operation of the aircraft's power plant.

At 40 degrees Celsius, 1 cubic meter of saturated air contains roughly
40 grams of water. (I leave it to you to convert this to US units.)
Hardly significant.

Stefan