I installed Weather Indicator for Ubuntu 11.04, but I can't find the information about the felt air temperature (like temperature is 30 degree, feels like 32 degree). How could I get that information? I can get this from old Ubuntu.
Unfortunately that feature is not in the current version of indicator-weather. The next major version (foggy) will have it. For the latest features and bug fixes (including felt air temperatures when they arrive), add our PPA: ppa:weather-indicator-team/ppa
If you want felt air temperatures now, then perhaps you should try My-Weather-Indicator, another weather indicator.
Disclosure: I'm involved with indicator-weather.