Apparently this April has been the warmest on record. Over 3 degrees higher than usual, and the warmest Spring since records began. Certainly the last few weeks have ususally been up in the 70's. I do have some strawberries in a growbag in the greenhouse that I was forcing for an earlier crop. The outdoor strawberries however, have been just as advanced and there seems to have been no difference indoor or out.
In order to stop the trusses of fruit from laying on the soil, I have laid straw round each plant so that the swelling fruit can rest on a dry surface. Hence they are called straw berries. It is only when the fruit is starting to swell that you can water and feed the plants with a high potash feed for a few weeks to help them on their way.