Both the timing and the weather is right for outbreaks of European red mites right now. Apple growers should be scouting their most susceptible varieties or blocks now. If you find problems, you should scout your entire orchard. There is a good chance that the infestation does not encompass your whole orchard, so only spray miticides on those areas where mites are in excess of the threshold. For more detail, go to https://extension.entm.purdue.edu/publications/E-258/E-258.html.