I use this site a lot to check out the forecast for my early AM rides and runs because you can find out the forecast temps, wind, humidity, chance of rain, etc. on an hour by hour basis. Most weather sites provide just a forecast high and low for the day with an estimate for the chance of rain during the entire 24 hour period. This doesn’t do you much good for finding out what the conditions will be like while you are on the swim, bike, and run portions of an IM. Click on the link below and scroll down to the table at the bottom labelled “Additional Forecasts and Information”. Click on “Hourly Weather Graph” for a set of 48 hour graphs providing NOAA’s forecast. You can change the start time of the 48-hour window in the window at the top.
This link gets you to the Madison, WI forecast. It’s a government site, so there are no ads or popups. I have found it to be pretty accurate, especially within about 72 hours. Beyond a 72-hour horizon, the accuracy drops off, but you will still get a pretty decent idea of temps and overall weather picture.
FWIW,
Greg
