I thought north winds were supposed to be cold. Although colder weather, in general, lies to the north, California is a little different. The direction of the wind tells you something about the air mass from which it originates. Since mountains lie to our north and northeast, the air has to drop in elevation as it moves southward into the Valley. That air loses eight to ten thousand feet of elevation.
Compression causes the air to warm.
So what you are feeling with a north summer wind is the air that started on a mountaintop then was compressed, heated, and forced towards us. The only kind of wind that really cools us down is the Delta Breeze. For much more on that local climate feature please look to the Weather Wizard section of today's Sacramento Bee . In it I go over the Northern California geography that plays SUCH an important role in our daily local weather. Those were both southeasterly winds.