An excellent working tool perfectly suited for the home observatory setup. This device includes:
a hygrometer (measures humidity, max and min for however long a time period you want)
a thermometer (again this control has a min/max setting, useful to see temperature change during an observing session, both celsius and fairenheit)
also has a very nice clock
This is a digital device, which I picked up a few months ago but have little need for anymore. Yours for 25 dollars including shipping. Contact me via email only please. Thanks for looking!