On Saturday, May 18, 2013, I completed the Fargo Marathon.  The site was selected for a few reasons including being close to family (my parents came over from Bismarck), and the fact that it is a very flat course.  I was shooting for my first sub-4 hour marathon, and the flat course would definitely help.  In 2011, I ran a 4:09 with somewhat minimal training.
I took a half day on Friday and drove up to Fargo alone, arriving at about 4pm.  I met my parents for an early dinner at 5pm at an Italian restaurant.  I ordered bowtie pasta with a red meat sauce.  I had been drinking lots of water that day and several prior, so I continued that at the restaurant.  Well, I snuck in a delicious glass of pinot noir to take the edge off.
I went to bed around 9:45 and slept like a baby until a thunderstorm worked its way through the area at about 3:30am.  I quickly went back to sleep and woke up at 5:30.  I felt pretty good.  Breakfast was a bagel with peanut butter, a banana, coffee, and Gatorade.
The drive to the Fargo Dome was longer than I expected.  There was a line of traffic virtually the whole way.  I'm glad I gave myself plenty of time.  The marathon started at 8:15am and I wanted to get there by about 7.  I ultimately arrived at about 7:15 and relaxed with a friend until heading outside at 8.  It was chilly (about 50) and cloudy at the start.  Perfect running weather, except a decent breeze right in our faces.
I didn't feel the need to wear a visor, apply sunscreen, or wear sunglasses - big mistake, but we'll get to that later.
I ran with said friend Corie, as we had the same goal of a sub 4 hour marathon.  We started out just behind the 3:50 pacer, figuring we could do about 8:50 miles for the first 20 and give ourselves time to do 10 minute miles for the final 6.2.  We were cruising along for the first 12 miles while the sun was still behind the clouds.  When the clouds went away, the entire race changed. 
We've had a very cold spring, so I was completely unprepared for the heat and humidity which descended upon us at about mile 14.  I could feel myself getting drained, and keeping the 8:50/mile pace became difficult very quickly.
I decided at about 15 that a 4 hour marathon was probably out of the cards, and may be even a little dangerous (I ended up in the hospital after a 2006 marathon).  So I decided to take as many walking breaks as I needed and run when I could for the final 10 miles.  It kept getting warmer and more humid.
Based on the splits below, you can see how the heat affected me:
1 - 8:51
2 - 8:40
3 - 8:55
4 - 8:42
5 - 8:56
6 - 8:55
7 - 9:14
8 - 9:08
9 - 8:58
10 - 8:56
11 - 9:08
12 - 9:08
13 - 9:17 (here comes the sun)
14 - 9:19
15 - 10:04 (walking breaks begin)
16 - 10:32
17 - 11:29
18 - 15:40 (I walked most of this mile)
19 - 12:38
20 - 14:29
21 - 13:27
22 - 12:37
23 - 14:58
24 - 13:23
25 - 12:59
26 - 12:21