While I was waiting for my API key to get activated I decided to test Weather underground through IFTTT, I had it trigger an event with some information and it looks like IFTTT still has accesses to Weather undergrounds API, so there may be a way for non "Super users" to get a daily event with sunrise, sunset, high and low temps, then set them to a map table to be used as they want.
they can get current weather and some other information but the event can only be triggered at a specific time, so you wouldn't be able request current weather, you would have to set the high and low for the day to a map or variable to be able to request it,
both commands you posted work well, I've been looking through the information in the response and it looks like it has a lot of the information that I'm after which is definitely good, but it looks like they aren't broken down by days (24 hour) they are broken down into three hour increments, so your second command gets the high temp of the current three hour window, it could be used for current weather, but determining today's high and low would be a little trickier.
I'm thinking it would be easiest to have IFTTT get:
Sunrise
Sunset
Today's High
Today's Low
and use openweathermap.org to get current conditions
as long as weather underground doesn't stop Ifttt from using their API, Then I think this will work