I recently changed both batteries on my indoor/outdoor thermometer. The external temperature is not displayed periodically. In it's place are 2 dashes (- -). This happens several days a week. Is there a way to fix it? (The internal temperature works fine.)

Sorry to tell you but the unit inside is kaput or going kaput. I have several of those wireless indoor/outdoor thingys and there are no fixable internal parts in the sending units or the indoor display unit. I just got another unit altogether and just use the indoor unit and threw the outdoor sending unit out. When the thing finally stops sending just pitch the outdoor unit and keep the indoor unit. I have the LaCrosse models that seem to work best. The other model that went kaput was an offbrand unit (Springfield Precise). The LaCrosse models I've had for years and one unit is in my moist bathroom 24/7 for years now and still works. The Weather Channel LaCrosse models work great for me as well. I like the little guy who takes his ooat off, shows the rain possibility and gets the time from the atomic clock. Had those 2 units for several years now and no problems.