My house has gas-powered hot-water radiators for heat. Ever since we moved in, I've noticed that if the temperature is just a bit chilly outside (40°F to 50°F), the house feels very cold and everyone needs to put on sweaters and sweatshirts.
But if it gets very cold (17°F or 30°F), then the house feels perfectly comfortable.
What could be going on here? I have a programmable thermostat, so I never change the settings. Depending on the time of day, it's set to betweeen 67°F and 70°F.