In most homes throughout New Hampshire and Massachusetts, radon levels will fluctuate with the seasons. During the summer and winter months, radon levels are more likely to be higher in your home. The windows and doors in your home are designed to be air tight in order to keep heat and cool air from escaping. While this is great, it also means harmful radon particles within the air are trapped in your home. So while your home is sealed up well during the summer and winter, radon levels will most likely be higher.