I use multiple web sites that provide essentially hourly weather forecasts:

weather.com
wunderground.com
usairnet.com
intellicast.com
local TV stations

I do not put much trust in forecasts farther than 10-12 hours in the future. I also check the radar to try to time when I leave work to avoid thunderstorms, especially during summer afternoons.

In addition, Google, Weather.com, local newspapers, local TV and others provide temperature and weather forecasts via text messaging. If you are not familiar with Google text services, then see: