PLS HELP!!! Radio clock, or "atomic clock" question?

Question

I'm looking at a couple atomic clocks, like the La Crosse Technology WS-8256U-AL or the Oregon Scientific JM889NA-S.

First, how do they get temperature readings? I'm looking for something that has an internal thermometer, without a separate wireless thermometer.

Second, I noticed that one of the atomic clocks I mentioned has weather forecasts -- where does it get this data from?

Finally, since both models I mentioned are the same price (on Amazon.com at least) is there any reason to go with one or the other, aside from the obvious fact that one has the added feature of weather data?

BTW: Do these atomic clocks just receive, and not transmit? I'm just making sure here.

Someone who knows the answers can get 10 points! THANKS!!!!

Answer 1

The temperature readings are from internal electronics.  Most clocks like that will give internal temps; some have the added feature of external (usually wireless) sensors for outside temps.

The "weather forecasts" are just based on the local barometric pressure and aren't particularly accurate.  For instance, rising pressure = sunny, but that could also indicate a front moving through and some rain, or falling pressure = rain, but that could mean the front is passed and the skies are clearing.

Umm -- transmit?  They are designed to receive the US atomic clock broadcasts on shortwave (5, 10, 15, and 20 MHz from Ft. Collins, CO or Hawaii) and interpret the signals to reprogram the clock to the correct time once a day (usually 1 to 4 AM local time).

You may find that the one with weather also has a relative humidity sensor.  If that would be useful where you live, then it might be a reason to choose it over the other.