I just wanted to offer some information on weather observations and forecasts that you can use in your decision making process regarding to biking. Some background - I am a degreed meteorologist with several years of experience who works for the Federal Government.
To begin with, Weather.gov is the main page for the National Weather Service. From the large U.S. map you can click on your local area, which will take you to your local office. For this example, I'll pretend I live in Minneapolis, so I'll click on central Minnesota and be taken to the NWS office in the Twin Cities. At the local office Web site, you'll see another map of the local area. Click anywhere on this map for a high-resolution, point-click forecast.
The forecast page that pops-up has a great deal of information. The icons at the top show you the weather for the next few days, with the text forecast for the next seven days located below the icons. To the right you'll find the Current Conditions from the closest weather observing station. If you click on "More Local Wx" you'll get a page of additional stations in the vicinity. Clicking on "3 Day History" will display the hourly weather observations for the past three days. Below that, you'll find links to satellite and RADAR images. Further down, a small map will show the local area - you can click on this map to get a new forecast and refine your forecast point.
Toward the bottom right corner you'll find many links. One of them will be the "Hourly Weather Graph". This will display the hour-by-hour forecast weather for the point you clicked on, including temperature, relative humidity, wind, precipitation chances, etc. You may also be interested in the "Forecast Discussion" - a semi-technical discussion written by a meteorologist detailing the thinking behind the forecast.
Finally, back on the main page of the local office (you can get back to it by clicking on the name of the office at the very top) there is a link to the "Activity Planner". This is a pretty neat tool that allows you to specify what weather conditions you are looking for or looking to avoid. For example, I can input that I want to know when the winds will be less than 10 MPH and the temperature below 80 °F, click on a point, and the resulting image will highlight the hours which are forecast to meet my criteria.
Hopefully this information has been useful. If you have any questions for me please ask. There is quite a wealth of information on the NWS Web pages, and each local office has some slightly difference features (some more, some less) so I suggest checking it out. I'll last mention the NWS RADAR Page, which you can use to access RADAR images/loops for anywhere in the country. And remember, this is all with no advertisements/banners as the NWS is paid for by your tax dollars (an average of $3 per person per year).