I picked most of mine today, only leaving the small ones outdoors on the plants. The reason for this is that so much wet weather will almost certainly finish off the tomatoes with blight which is already spreading through the country, and then the lot will be lost virtually overnight. I've laid mine on trays lined with newspaper on the window sills and they ripen very quickly. Also, a sudden drop in night time temperature could cause the tomatoes either to split or the skins to become so damaged that they start to rot quickly.