2005 Ford F-150 Trouble Starting

This problem happened about a month ago, yesterday and this morning. As I turn the key to start the pickup the starter turned over for just a second then stopped. The power to everything is cust for a second because the radio and clock has to be reset. Whe I turn the key the second time the pickup starts up. I'm in south Texas so the temperature is humid and atou 50 degrees when this happens.